In this residential type are all habitational structures located on the summits and prominences of mountains, ridges, hills, and high rock formations. By the very nature of these geographic locations, such monuments have an inherent defensive aspect to a lesser or greater extent. Among this residential type are edifices that functioned as fortresses and citadels (habitations designed and built for military purposes), temples and hermitages (buildings with a religious or ceremonial function), palaces (social elite residential buildings), and breastworks (networks of ramparts or other types of defensive structures that were temporarily or permanently inhabited). It must be noted that, from a visual appraisal alone, the specific occupational functions of individual edifices or components thereof can only be inferred. In any event, these strongholds, temples, palaces, and hermitages appear to have been where the ruling and priestly classes exercised their social influence and political control over the agriculturalist and pastoralist sectors of society.

I.1a) All-stone corbelled buildings

Type I.1a. An artist's conception of an all-stone corbelled citadel with staggered ramparts in the foreground (drawn by Kleo Belay)

This building subtype represents one of the most prominent classes of residential structures found in Upper Tibet. In the parlance of the region, this style of architecture is often referred to as dokhang (all-stone habitation). This form of construction is characteristic of the archaic cultural milieu of the region, and is eminently well suited to the environmental exigencies of the harsh landscape. It is in Upper Tibet that all-stone corbelled buildings reached their fullest architectural expression in all of Central Asia. This building design is exceptionally rugged and structurally stable, and individual examples may, in some cases, have endured as habitations for centuries.

All-stone structures feature the use of corbels, stone members that were placed on the upper extent of walls as load bearing devices for the stone roof assembly. Corbels were simply rested on the tops of walls or were inserted into specially built wall sockets. Corbels act to support bridging stones and stone sheathing from which the roof was made. Bridging stones were laid diagonally or crosswise in one or more courses over the corbels in order to span the distance between opposite walls. In turn, large slabs of stones were placed upon the bridging stones to create a complete roof covering. The elementary corbelling technique employed in Upper Tibet for roofs was only suited for use over small interior spaces (typically 3 m² to 12 m²). Large edifices were created by juxtaposing multiple, structurally self-contained rooms or groups of rooms together to form a contiguous ground plan. In some places (such as sites A-10 and A-54) corbels with sockets were used to support the stone flooring of a second story in the same fashion as roofs were constructed.

All-stone corbelled edifices have many unique design traits. In general, they are massively built, a consequence of the great weight that the roofs bear on these structures. Walls are between 60 cm and 1.2 m in thickness, and of a slab or block random-rubble texture. Both dry-mortar and clay-mortar seams are represented in their construction. Roofs are, as a matter of course, flat and originally must have been layered in gravel and clay to weather-proof the buildings (little evidence of this more ephemeral aspect of construction has survived). As each room or group of rooms is an isolated unit structurally, the exterior walls of such structures have an irregular or even a meandering plan. Walls are of variable thickness, with various exterior indentations and interior recesses common. Both exterior and interior corners tend to have a rounded quality, as this facilitates the arrangement of corbels. Interior walls are punctuated with buttresses that function to support intervening series of corbels and roof appurtenances, especially in larger rooms. The floor-to-ceiling height of rooms in dokhang is usually relatively low (1.6 m to 2 m). Most buildings are windowless and even in certain structures where there are interior and exterior window openings, these are small in size.

Single buildings contain between two and one dozen rooms, which are normally arranged in rows or isolated aggregations. Rooms directly open onto one another or are connected through a small corridor or interclose. Various wings in a single building usually had separate exterior entrances, as large interconnecting halls and galleries are not possible in dokhang construction. Another defining feature of the all-stone corbelled edifices is the very small size of their doorways; these average only around 1.1 m in height. The lintels of the entranceways (and the few windows) are made from stone. The heavy windowless walls and low doorways of the rooms indicate that they must have been weatherproof and easy to heat. Collections of small rooms also indicate that a decentralized or compartmentalized domestic ecology was the norm. Individual cells must have been set aside for the various facets of everyday life such as sleeping, food preparation, storage of provisions, and religious observances. Rooms were only large enough for individuals or small family units. Cooking, meetings and ceremonial life inside the dokhang could only have revolved around small groupings of people.

Customarily, sundry dokhang on a summit were vertically interconnected to create a staggered array of structures. Naturally occurring rock outcrops and ledges were commonly used to help support corbelled buildings and to act as one or more walls of the structure (particularly in the rear). This form of construction is very favorable to incorporation into the adjoining terrain, as walls could be built to accommodate the twists and turns of rock faces. This high degree of integration with the parent formation is a distinguishing feature of dokhang design. Although corbelled edifices individually have low architectural elevations (there are no high ceilings in rooms, and parapet walls where they exist appear to have been minimal), the stacking of one on top of another has the effect of producing formidable complexes. It is not uncommon to find these clinging to the sheer walls of a summit for many vertical meters. In sites that appear to have functioned as hermitages, individual residences tend to be separated from one another rather than forming aggregated complexes. The use of prominent revetments, a common feature, significantly increased the elevation of exterior faces. Revetments function to give buildings a stable foundation and to even out the dips and rises on rocky summits. Rather infrequently, all-stone edifices were integrated with other building types at a single site. Occasionally, there is also evidence to suggest that the basement or lower story of a building was fashioned as a dokhang, while the superstructure was of an alternative style of construction (see site A-51).

The wide distribution of dokhang through most areas of Upper Tibet and their superb adaptive bearing indicates that they were a chief residential type for a long period of time in the region. Bronze Age occurrences of corbelled edifices in regions like the British Isles and Mediterranean may suggest that this form of architecture developed in Upper Tibet at a relatively early date. The lack of demonstrable monumental precedents in the archaeological record of Upper Tibet reinforces the impression that all-stone edifices have a very long legacy behind them. Chronometric data on the sites surveyed are now undergoing compilation; these results furnish the best archaeological evidence corroborating the archaic nature of Upper Tibet’s all-stone edifices.¹

I.1b) Edifices built with timbers

This heterogeneous monument subtype includes all residential structures that were built with roofs containing timbers. Among the examples included in this inventory may be sites that were actually founded or redeveloped after the early historic period that could not be differentiated from older strongholds (because of the possession of similar morphological and cultural attributions). Further archaeological investigation will be required to clear up this typological ambiguity. Edifices constructed with wooden roofs located on summits generally have a good defensive posture. As with the all-stone corbelled structures, their domiciliary usage appears to have varied greatly. Citadels, fortified settlements, temples, and palaces are all probably represented among this class of habitation. These timbered edifices are of four major wall fabrics:

1. Random-rubble and coursed rubble stone walls
2. Adobe or unbaked mud block walls (sapak)
3. Rammed-earth or shuttered walls (gyang)
4. Walls of cut earthen slabs

i) Residential structures built with stone walls are commonly encountered throughout Upper Tibet. Where walls are left standing, this type of construction is readily identifiable: walls are straight and regular and can be of considerable length. As roofs were built with wooden timbers, the walls supporting them were not required to be as massive as structures with much heavier all-stone roofs. The regular buttressing and indentations of dokhang walls is also conspicuously absent. Moreover, high elevation profiles and large rooms and halls are found with much frequency, especially among Buddhist complexes. However, what appear to be archaic structures built in this manner share some of the customary features of dokhang design. These include edifices with smaller rooms, windowless walls, relatively low entranceways, adeptly constructed random-rubble slab walls, a high degree of topographical integration into the parent formation, the proliferation of small buildings staggered vertically across a summit, and series of small ramparts.

None of the stone wall buildings surveyed have their roofs intact but the general constructional pattern and the rare presence of timber fragments suggests that roofs were constructed much as they were in the Central Tibetan style of architecture. This entails the laying of timbers across the top of walls and covering them with wooden and/or stone interlinking materials. Once the roof was completed in this fashion, wattle, clay and possibly Tibetan cement (arka) must have been used to build successive enclosing layers. Unlike the traditional architectural landscape of Central Tibet and Eastern Tibet, there is no evidence of towers having been erected in Upper Tibet, stone buildings of more than two stories being rare in the region.

A site attributed to the ancient Mön in the oral traditions of Upper Tibet Kapren Gyanggok (A-33) was in use as late as the 13th century CE. Chronometric data obtained from Kapren Gyanggok reinforces the view that monuments attributed to the Mön must be understood in a broad historical and cultural framework.

ii) Residential structures built with adobe blocks are commonly encountered in Gugé, that large Transhimalayan badlands region in the Sutlej (Langchen Tsangpo) drainage area of deep gorges and highly eroded earthen formations. While mud-brick walls are common in Buddhist era buildings (such as monasteries and retreats) in the Jangtang, there is scant evidence that such structures were established in pre-Buddhist times. One exception may be a complex of buildings at Drakgam Dzong (B-40). It was founded on a slope overlooking the Mukyu Tsangpo basin, a rich pastureland.

Adobe block edifices were founded in great numbers in Gugé in the Buddhist era. According to the local oral tradition, they were established in the prehistoric epoch and had been the handiwork of that elusive tribe the Mön or Kel Mön/Kel Mön.² From an environmental perspective, this claim of antiquity for elementary earthen structures is plausible, for building stones are in short supply in many corners of Gugé, and lithic materials appropriate for corbelling and bridging only very seldom occur. The antiquity of adobe block constructions is also supported by recently compiled chronometric data from the Rula Khar site (A-141) (see below). Systematic survey of sites in Gugé, to which oral tradition assigns an archaic identity, has brought to light physical evidence, which tentatively permits adobe structures to be chronologically differentiated from one another. One distinguishing criterion employed in trying to determine what may be examples of archaic adobe edifices is based on an analysis of building design. Sites such as Hala Khar (West) (A-58) strongly contrasts with known Buddhist architecture of the region. Its highly exposed and isolated aspect, unusual ground plan and extremely deteriorated condition are circumstantial evidence for the inclusion of Hala Khar (West) in the category of archaic monuments. This single 32 m long contiguous complex consists of four rows of tiny rooms that run parallel to the axis of the summit at different levels. No Buddhist monuments or emblems are found at Hala Khar (West) and no Buddhist religious lore is attached to the site.

The survey of citadels and other summit residential structures attributed to the ancient Mön in the localized traditions of Gugé demonstrates that most of the facilities exhibiting mud brick wall construction are in fact primarily built of stone. At most so-called Mön sites adobe walls were used for relatively minor constructions and for upper wall courses. What adobe walls do exist are as a rule much more highly eroded than Buddhist constructions. At none of theMön castles (möngyi khar) are there large, high-walled buildings (lhakhang, dükhang, etc.) like those found at virtually every Buddhist monastery in Gugé. Moreover, sites attributed to the archaic period of construction are often associated with troglodytic communities with few or no signs of Buddhist occupation. A foundation or refurbishment date of circa 565 to 705 CE is indicated for the adobe block northwest edifice of Rula Khar (A-141). The relative position of the radiocarbon assayed sample in the building confirms that adobe block constructions were indeed part of the archaic architectural canon of Gugé.

iii) Rammed-earth residential structures that local oral tradition places in the archaic period are limited in geographic range to lower elevation western Ngari Korsum and in particular, to Gugé. A single wall of this construction type attributed in the oral tradition to the Zhangzhung kingdom is found at the high point of the Takla Khar fortress (A-81) in Purang. In Gugé, summit strongholds such as Jangtang Khar (A-116) and Sharlang Khar (A-118), two castles that in the local oral traditions are assigned to the Kel Mön, have rammed-earth structural remnants. Walls of this type, nevertheless, are found at only a minority of strongholds attributed to the ancient Mön in Gugé. The technological origin and chronology of rammed-earth walls, built by packing wet earth and clay with a stone matrix between large wooden shutters, is not at all certain. It may be that rammed-earth structures are wrongly attributed in legend to the archaic period or that they were founded at sites with structural remains from earlier periods of occupation.

iv) At just a few fortified sites in Gugé another type of wall was formed from naturally occurring compressed slabs of earth, which were cut from the native formations. Structures built with this type of wall dominate at Cholo Puk (A-113) and Rakkhashak Möngyi Khar (A-115), strongholds attributed by local residents to the Mön. At Cholo Puk, a sequence of chambers were cut out of the long flat summit, and the slabs resulting from the excavation used to build walls above the top of the excavated chambers. Parapet walls were also built around the edges of the summit using the same natural earthen slabs. The absence of monuments indicative of Buddhist occupation at these sites, as well as their semi-subterranean aspect, encourages the view that earth slab fortifications do indeed date to the era of archaic residential structures.

I.1c) Solitary rampart networks

Type I.1c. A staggered rampart network with parapet wall on summit; a reconstruction of the basal structural elements (drawn by Kleo Belay)

Some strongholds in Upper Tibet are exclusively composed of networks of defensive walls traversing summits and adjoining slopes. At sites such as Namdzong (A-48) and Takzig Nordzong (A-50) there appear to be few, if any, residential buildings, but rather a series of ramparts fortifying a strategic mount or rock formation (those in proximity to a high quality pasture or important pass). These random-rubble dry-mortar breastworks consist of long walls that wind across slopes vulnerable to attack. Typically, the walls are 1 m to 2 m high on the downhill slope, and slightly elevated or flush with the uphill side of a slope. These defensive structures are normally around 1 m to 2 m in width, and between 2 m and over 100 m in length. Parapet walls or ledges were probably built on the outward projecting edge of the ramparts but much of the structural evidence for these features has disappeared down the slopes with time. A chief characteristic of rampart network design and deployment is that they appear in multiples, each wall running in a transverse direction at different elevations and somewhat parallel to one another. An approachable slope may have upwards of eight successive ramparts, one above the other, guarding the higher and more vital reaches of a site. In addition to being aligned in parallel, defensive walls join one another or branch out in different directions across ribs of rock and broad acclivities. Some of the wider, more level and sheltered breastworks appear to have functioned as platforms for camps and the garrisoning of fighters. The intricate arrangement of breastworks as the exclusive or dominant architectural component of a fortified site bespeaks a special form of defensive posturing by which entire rock formations functioned as strongholds.

While some sites seem to have been comprised entirely of breastworks, most of the archaic fortifications of Upper Tibet heavily relied on them for defense. At many citadels, defensive walls form an integral part of the complex. These are of three major types: 1) those staggered below residential structures that are erected on a summit; 2) those that encircle the main nucleus of habitation (circumvallations); and 3) those that connect various residential structures (curtain-walls).