Upper Laos – Northeastern Laos, Houaphan and Xieng Khouang provinces – is one of the most mysterious regions in Indochinese Peninsula, known for the ancient megalithic civilization that has left a treasure trove of jars, funeral stones, monoliths and menhirs scattered across the land, as well as the mysteries surrounding certain episodes of the American Secret War in Laos.

Reportedly built by King Po Kathit of the Kramuka lineage (the Areca clan), the ancient citadel of Bal Hanön was the last capital-citadel of the Cham and one of the first capitals of Panduranga, the southernmost Cham kingdom that today occupies the center of Binh Thuan province in southern Vietnam.

In 150 AD, the Roman geographer and mathematician Ptolemy plotted a map of the ancient world in his influential work Geography, pinpointing the port of Kattigara east of the Golden Chersonese (Malay Peninsula) located in Magnus Signus (the Gulf of Siam). Kattigara – located in modern-day Ba The Mount, a small mountain range of rugged granite formations in An Giang province, Vietnam – is widely accepted by scholars as the archaeological site of Oc Eo.

For centuries, the South China Sea was known by navigators throughout Asia as the Champa Sea, named for the ancient Kingdom of Champa – an enduring power that lasted over 1,500 years in central and southern Vietnam.