Photographs from the excavation of the "underground city" in Tbilisi

Grandiose subterranean halls with vaulted tiers came to light in August during repair work in the courtyard of the Melik-Azaryants tenement house on Rustaveli Avenue, on the side towards Republic Square. Naturally, talk of buried cities at once revived, which is, on the one hand, perfectly understandable: how can it be that beneath a house still in use there lie such vast underground premises, several storeys deep, and yet they turned out to be empty, with nobody knowing of them?

Against this background, the official answer, that a certain merchant simply decided to build colossal underground storerooms beneath his tenement house, does not look very convincing.

But it is not so simple. It is known that the tenement house, built between 1912 and 1915, was raised on a most inconvenient plot with a ravine and groundwater, and complex underground engineering structures of arches, piers and vaults were designed from the outset to hold up a five-storey building. These tiers were not subsequently abandoned: they were in use, housing water-supply pumps, boiler rooms, coal stores, a power station and other service premises. In the Soviet years, however, the need for autonomous utilities fell away, and several thousand square metres of underground space fell empty. It is reported that in the 1990s commercial bars operated on the upper tiers of the vaults. And, naturally, the residents of the house knew that such a peculiar space existed beneath them.

But the visual effect produced by the sweep of this construction is a powerful one.