Arena is the name of the amphitheatre located in Pula, Croatia. The Arena is the only remaining Roman amphitheater to have four side towers and with all three Roman architectural orders entirely preserved.
The ruined citadel of Koshoy Korgon, is located just outside of the village of Kara-Suu. Not much is known about this fortress (at least according to my guidebooks, anyway) but it dates from roughly the 10th century, and was probably Karakhanid.