Why was Thailand so important back in it's days?

The Kingdom of Thailand is one of the few developing countries never to have been colonized. It is located centrally in Southeast Asia with both extensive Pacific coasts (Gulf of Thailand) and Indian Ocean (Andaman Sea). It shares borders with Myanmar (Burma) to the west and northwest, the Lao PDR to the north and northeast, Cambodia to the south and east, and Malaysia to the south. Thailand occupies an area of 514,000 square kilometers (319,194 square miles). Its population is 61,230,874 (estimated in July 2000), making it the sixteenth largest country in the world.

I don’t know may not be what your looking for

Arctic temperate greenhouse