Tmogvi fortress is built on a high rocky mountain. Because of the peculiarities of the terrain its ramparts rise at different levels. The western part of the fortress is comparatively well preserved: here it is built up the gentle rock slope in three tiers of walls and bastions. On the southeast the wall abutted a cave which was linked by a secret tunnel cut in the rock to the citadel above and to the Mtkvari River below. The small area at the fortress's heart was entirely occupied by buildings. A rectangular structure raised on a basalt socle, built of dressed tuff blocks and covered with a gabled roof, was evidently a church. Two main layers can be distinguished in the masonry of Tmogvi fortress: the oldest is built of even courses of dressed tuff blocks, while the walls of roughly worked rubble stone belong to the era of later rebuilding and reconstruction. Outside the fortress walls, in the ravine to the west, is the church of St. Ephrem carved into the rock massif, with a chancel screen likewise cut from the rock; in the ruins of a second, domed church survive fragments of 13th-century wall painting. On both banks of the Mtkvari are abandoned village sites and the ruins of palaces. The palace ruins on the left bank belong to the oldest building layer, those on the right bank to the later one, dated to the mid-14th century, where a bath and three other buildings can be distinguished. The bath, built of Georgian brick and stone, comprises three rooms; its vaults have collapsed, though the character of the corner squinches is discernible. Near the palace run two roads: the path from Tsunda passes east of the palace and led past the Vanis Kvabebi caves toward Vardzia; the other is the historic road for transport, beginning near the village of Margatastani, passing the palace, then descending into the valley by a footpath to join the bridge. Remains of bridge piers survive on the Mtkvari: one bridge linked the palaces, the other was meant for transport. The fortress town was destroyed several times by powerful earthquakes (1089, 1283, 1319 and others).