Excavation at Óc Eo began on February 10, 1942, after French archaeologists had discovered the site through the use of aerial photography.
The first excavations were led by Louis Malleret, who identified the place as the Cattigara of Roman merchants in the first centuries of the Roman empire.
The site covers 450 ha.

Óc Eo is situated within a network of ancient canals that crisscross the low flatland of the Mekong Delta.
 One of the canals connects Óc Eo to  the town's seaport while another goes 68 kilometres (42 mi) north-northeast to Angkor Borei.
 Óc Eo is longitudinally bisected by a canal, and there are four transverse canals along which pile-supported houses were perhaps ranged.

Archaeological sites reflecting the material culture of Óc Eo are spread throughout southern Vietnam, but are most heavily concentrated in the area of the Mekong Delta to the south and west of Ho Chi Minh City.
 The most significant site, aside from Óc Eo itself, is at Tháp Muời north of the Tien Giang River, where among other remains a stele with a 6th-century Sanskrit text has been discovered.

Aerial photography in 1958 revealed that during the Funan period a distributary of the Mekong entered the Gulf of Thailand in the vicinity of Ta Keo, which was then on the shore but since then become separated by some distance from the sea as a result of siltation.
At that time, Ta Keo was connected by a canal with Oc Eo, allowing it access to the Gulf.
The distributary of the Mekong revealed in the aerial photography was probably the Saenus mentioned in Ptolemy’s Geography as the western branch of the Mekong, which Ptolemy called the Cottiaris.
The Cattigara in Ptolemy's Geography could be derived from a Sanskrit word, either Kottinagara (Strong City) or Kirtinagara (Renowned City).
Excavation at Óc Eo began on February 10, 1942, after French archaeologists had discovered the site through the use of aerial photography. The first excavations were led by Louis Malleret, who identified the place as the Cattigara of Roman merchants in the first centuries of the Roman empire. The site covers 450 ha.
Óc Eo is situated within a network of ancient canals that crisscross the low flatland of the Mekong Delta.  One of the canals connects Óc Eo to  the town's seaport while another goes 68 kilometres (42 mi) north-northeast to Angkor Borei.  Óc Eo is longitudinally bisected by a canal, and there are four transverse canals along which pile-supported houses were perhaps ranged.
Archaeological sites reflecting the material culture of Óc Eo are spread throughout southern Vietnam, but are most heavily concentrated in the area of the Mekong Delta to the south and west of Ho Chi Minh City.  The most significant site, aside from Óc Eo itself, is at Tháp Muời north of the Tien Giang River, where among other remains a stele with a 6th-century Sanskrit text has been discovered.
Aerial photography in 1958 revealed that during the Funan period a distributary of the Mekong entered the Gulf of Thailand in the vicinity of Ta Keo, which was then on the shore but since then become separated by some distance from the sea as a result of siltation. At that time, Ta Keo was connected by a canal with Oc Eo, allowing it access to the Gulf. The distributary of the Mekong revealed in the aerial photography was probably the Saenus mentioned in Ptolemy’s Geography as the western branch of the Mekong, which Ptolemy called the Cottiaris. The Cattigara in Ptolemy's Geography could be derived from a Sanskrit word, either Kottinagara (Strong City) or Kirtinagara (Renowned City).
Óc Eo