1. Angkor Thom
Angkor Thom was the last and most enduring capital of the Khmer Empire, a walled city covering 9 square kilometers that remained the seat of power until the 15th century. King Jayavarman VII built it in the late 12th century, and the sheer ambition is staggering. Five monumental gates, each topped with four stone faces and flanked by rows of gods and demons pulling a naga serpent, lead into what was once home to an estimated one million people. Bayon Temple sits at its geographic center. Beyond Bayon, the city contains the Terrace of the Elephants (a 300-meter-long platform carved with life-size elephant reliefs), the Terrace of the Leper King, and several smaller temples. Most visitors drive through the South Gate, which is the most photogenic and the most photographed. The road itself runs through dense forest, and the sensation of entering through that carved gate is one of the great arrivals in all of Southeast Asian travel. Unlike the focused experience of a single temple like Ta Prohm, Angkor Thom is a whole city to explore. The compound is open daily 8:00 AM to 9:00 PM.