Sri Lanka: Anuradhapura
The Sacred City of Anuradhapura is the most important archeological monument in Sri Lanka. It served as the political and religious capital of the country for over 1300 years from about 3rd century BC to 993 AD when it was sacked in an invasion. As such, it is one of the longest and most stable centers of a civilization in history. It’s a massive and sprawling city of ruins and sacred religious sites. There are several big dagobas (stupas) that are millennia-old and up to 340 m/1100 ft in circumference. There are stone platform and pillars from the old building, some ornate with carvings. There are ancient baths, pools, and water tanks. There are several fantastically- preserve moonstones. All of this is interspersed with trees and tropical jungle. It’s a UNESCO World Heritage sight and one of the most important archeological remains on the planet.