Ak Yum, sometimes written Akyum or Ak Yom or called Prasat Ak Yum, is pronounced "Ok Yoom", the "O" of "Ok" is open, the "k" is nearly not audible.
Ak Yum is a construction from the late 8th century, sometimes ascribed to the legendary founder of a united Khmer empire at the begin of the Angkor era, King Jayavarman II.
Ak Yum was a small artifical temple-mound in the centre of a pre-Angkor city now called Banteay Chheu. The name used for this pre-Angkor era is Chen-la (Zhenla), as this is the name mentioned in Chinese records for Cambodia's kingdoms, those of the 7th and 8th century in particular. Probably, this Banteay Chheu area then served as one of the successive capitals chosen by Jayavarman II. Even after the city of Angkor was established ten kilometres further east, at the Bakheng hill, Banteay Chheu remained to be an important settlement. But parts of it later on were covered by the reservoir West Baray, which was built in the 11th century.
Ak Yum is located at the base of the south dike of the West Baray, partly covered by it. The site was excavated in the 1930s under the direction of the French archaeologist George Trouvé.
Inscriptions indicate that a temple dedicated to a “god of the depths” was previously located on the same spot. The first structure on the site was only a single-chamber brick sanctuary. According to excavations in the 1960s there must have been even a prehistoric site near the later Ak Yum temple.
There is not much to see at the present-day Ak Yum. The pyramid is not impressive any more, and its original appearance is hardly recognizable for non-scientists. But Ak Yum is historically remarkable as it was the first pyramid-temple in Khmers architecture. Originally the pyramid structure had a basis of about 100 metres square. Such an artificial mound with stepped levels, serving as a monumental pedestal for Prasat buildings, became one of the characteristics of the state temples in the Angkor era. Ak Yum can be regarded as their small prototype.
The best time to visit Ak Yum is the late morning, between 10.00 am and noon. You do not need a ticket, neither to visit the West Baray area nor for access to the Ak Yum ruins.