Thommanon underwent a major reconstruction thanks to the Ecole francaise d’Extreme-Orient (EFEO) and is now in remarkable condition. Like many monuments this was originally a walled-in structure, but the outside wall has largely collapsed leaving the gopuras standing alone almost like mini-temples in their own right. Chau Say Tevoda, also a flat temple with a similar layout, sits opposite Thommanon to form a pair.
Probably started by Jayavarman IV and continued by Dharanindravarman I, it seems to have been completed by Suryavarman II around the middle of the 12th century. (Dharanindravarman’s influence is shown by the presence of some Buddhist imagery at this temple.)
Thommanon is a flat temple, with all elements on one level and a dominant tower. Many of the site’s lintels are worn but the site is noteworthy for some of the female devatas with their fancy headgear that flank some of the sanctuary walls.