Kalon Minaret

When it was built by the Karakhanid ruler Arslan Khan in 1127, the Kalon Minaret was probably the tallest building in Central Asia - kalon means 'great' in Tajik. It's an incredible piece of work, 47m tall with 10m-deep foundations (including reeds stacked underneath in an early form of earthquake-proofing), which in 850 years has never needed any but cosmetic repairs. Jenghiz Khan was so dumbfounded by it that he ordered it spared.

Its 14 ornamental bands, all different, include the first use of the glazed blue tiles that were to saturate Central Asia under Timur. Up and down the south and east sides are faintly lighter patches, marking the restoration of damage caused by Frunze's artillery in 1920. Its 105 inner stairs are accessible from the Kalon Mosque.

A legend says that Arslan Khan killed an imam after a quarrel. That night in a dream the imam told him, 'You have killed me; now oblige me by laying my head on a spot where nobody can tread', and the tower was built over his grave.