Complex sentence: Another significant Kidan city was Bars-Hot existed in the basin of the river Kerulen, occupying an area of 1600x1810 metros, surrounded with mud walls which are today 4 metres thick and 1.5--2 metres high.
Split into simpler sentences: Another significant Kidan city was Bars-Hot in the basin of the river Kerulen. It occupied an area of 1600x1810 metres and was surrounded with mud walls, which are today 4 metres thick and 1.5--2 metres high.