The Tatar fortress here was destroyed by Ivan the Terrible when he captured the area in 1551. Over the next century, it was rebuilt in Russian style as a magnificent Kremlin, with new fortifications and a cathedral. It nowadays also contains a mosque, museums, galleries, shops and cafes, and is inscribed on the UNESCO World Heritage list. Enter through the white clock tower (Spasskaya Tower) at the top of Kremlyovskaya Street. Unlike Moscow's Kremlin, you're free to enter and stroll, but you pay for individual sites within the complex. These are lined along the central boulevard, mostly on the left as the buildings on the right are under reconstruction. They're listed below roughly south to north, in the order you'd come to them. Allow a full day to appreciate them all. Guided tours are available for 300 руб, but you won't get lost here.