Ichan Kala is the walled inner town of the city of Khiva, Uzbekistan. Since 1990, it has been protected as a World Heritage Site. The old town retains more than 50 historic monuments and 250 old houses, dating primarily from the eighteenth or nineteenth centuries. The most spectacular features of Ichan Kala are its crenellated brick walls and four gates, one at each side of the rectangular fortress. Although the foundations are believed to have been laid in the tenth century, present-day 10-meters-high walls were erected mostly in the late seventeenth century and later repaired.