Kyzyl-Kala, also Qyzyl Qala ("Red fortress"), in modern Karakalpakstan, Uzbekistan, was an ancient fortress in Chorasmia built in the 1st-4th century CE. The small fortress of Kyzyl-Kala is located near Toprak-Kala, about 1 km to the west, and was also built in the 1st-4th century CE, possibly as a fortified defense for the site of Toprak-Kala. Kyzyl-Kala was once restored in the 12th century CE. It has also been the subject of a modern renovation program, with the objective of showing what a fortress looked like originally. It is part of the "Fifty fortresses oasis" in modern-day Uzbekistan. It was last occupied by Muhammad II of Khwarazm (1169, 1200-20), before it fell to the Mongol conquest of the Khwarazmian Empire.