Karakorum, the Mongol capital, is presented as little more than a large cluster of tents. Actually, it was a cosmopolitan city with walls and stone buildings, including stupas, churches, mosques and the Palace of the Khans.
By 1273, when the episode is set, the Toluid civil war between Kublai and Ariq Böke has been over for nine years, and Ariq dead for seven.