You are free to walk around the Ichon-Qala without a ticket, you just won’t be able to access (or, technically, to photograph) any sights. The North , East and South Gates are known as, respectively, the Bogcha-Darvoza (Garden Gate), Polvon-Darvoza (Strongman’s Gate) and Tosh-Darvoza (Stone Gate), but the main ticket office can be found in the twin-turreted West Gate (Ota-Darvoza, literally ‘Father Gate', a 1970s reconstruction – the original was wrecked in 1920), the main entrance to the old city. One highlight for which no ticket is needed is the walk along the northwestern section of the wall. The stairs – such as they are – can be found at the North Gate. The 2.5km-long mud walls date from the 18th century, and were rebuilt after being destroyed by the Persians.