Bukhara

Two and a half thousand years of city on the Silk Road, and the place where a single building survived by being buried. When Genghis Khan besieged Bukhara for fifteen days in 1220 and then levelled most of it, the tenth-century Samanid Mausoleum came through because flooding had already packed it in mud and it was effectively invisible. The Kalyan minaret still stands 45.6 metres with a nine-metre base and a brick spiral stair coiling up inside it to a sixteen-arched rotunda; for centuries it doubled as a landmark for caravans and, less happily, as a place of execution. The Ark, the emir’s citadel, held the centre of town until the Red Army wrecked it in 1920. UNESCO listed the historic centre in 1993. About 140 miles west of Samarkand.