Ulaanbaatar is a very walkable city and offers so many sites we were actually not expecting. We really liked the Gandan Monastery, this is an impressive sight, and there are actually several buildings to explore. The Avalokiteśvara statue is the tallest indoor statue and a must-see. The Black Market is also really interesting and is nice to “get lost” as you wander around the different alleys. The Bogd Khan Temple has seen better days but as the only left building from the original residence that hasn’t been destroyed during the war and post-war era, it is definitely worth seeing. One can picture how the city must have been back then.