The amphitheater commemorates all civilians who were killed on October 14, 1973, during a student uprising against the Thai government. The protest was brutally suppressed and turned into a riot, which resulted in many deaths and ended the military dictatorship.
More information http://bangkokforvisitors.com/districts/khaosan/14-october-memorial.php
Address Thanon Tanao, Bowon Niwet, Phra Nakhon, Bangkok 10200, Thailand
Coordinates 13°45'24.5" N 100°29'56.779" E