The most impressive member of the Roulos Group, Bakong sits
at the centre of the first Angkorian capital, Hariharalaya.
Bakong stands 15 meters tall and is 650 m x 850 m at the outer
wall. Constructed by the third Angkorian-era king as his state-temple,
Bakong represents the first application of the temple-mountain
architectural style on a grand scale and set the architectural
tone for the next 400 years. The temple displays the early use
of stone instead of brick. Alyhough begun by Indravarman 1,
Bakong was expanded by later kings. The uppermost section and
tower may have been added as late as the 12th century A.D. Some
of the lintel carvings, particulalry on the outer towers, are
in very good shape.