The South Khleang, opposite to the huge Baphuon, is the slightly smaller twin temple of the North Khleang. It was erected in the first half of the 11th century under Suryavarman I (1010-1050). As in the case of the northern Khleang the purpose of the building is under debate. The modern name "Khleang", sometimes spelt "Kleang", means "store house", this is not neccessarily a misinterpretation. The Khleangs could have sheltered royal treasures for ceremonies on the Royal Square. In this case, the Khleangs could have been secular stone buildings and sacred monuments at the time, as almost certainly the royal treasure contained works of art of religious significance.
There is inscriptional evidence that the South Khleang was built a few decades later than its counterpart, the northern Khleang. The addition of the second Khleang in 400 m distance on the same north-south line, obviously, was inspired by the idea of symmetry. The Royal Palace facing the Royal Square already existed in the tenth century, two centuries later on it was integrated into the layout of Angkor Thom. The symmetry axis between northern and southern Khleang, right-angled to the palace facade and to the Khleangs, was the axis of the Royal Palace, too, and later on became the "Victory Avenue" leading to Angkor Thom's Victory Gate to the east. The symmetry is reinforced by two pools flanking both Khleang edifices on both sides of this avenue. The pools are 90 m long and 48 m wide. Furthermore, the 12 towers of Prasat Suor Prat, added later on, were arranged symmetrically to the very same axis.
The South Khleang is uncompleted. The long hall was shorter than the northern edifice, only 45 m. The width of the South Khleang hall is 4.2 m, slightly narrower than that of its sister temple. It has not a kind of central square tower like the North Khleang. There is much less decoration at the southern Khleang, and it is less carefully worked out. Exceptions are a frieze under the cornice and the elegant colonettes framing the east doorway of the chamber at the southern end. The South Khleang is the only monument inside Angkor using the same red sandstone Banteay Srei is famous for, but here are no remains of lintel carvings made of this special stone. Only colonettes of the South Khleang are of this extraordinarily tough kind of sandstone.
You should have an Angkor ticket to stroll around in Angkor Thom. Both fronts of the edifice are impressive, so you will see one of them in the sunlight whenever you come. Noon is a good time to visit the interior corridor, which is roofless. So visit the Khleangs any time you like to spend here, on the way to the more important monuments.