Sri Lanka's sightseeing is underrated relative to the country's famous interior sites. The national museum holds royal regalia and Buddhist bronzes of considerable beauty. The ancient cities circuit — the oldest historically documented tree in the world, the 5th-century rock fortress with frescoes, and the cave temples — forms the country's essential inland sightseeing arc. The colonial layering of Portuguese, Dutch, and British periods is visible in architecture and street names. Yala National Park carries the highest leopard density per square kilometre of any national park in the world. The Sinharaja rainforest endemic bird watching is one of Asia's most specific wildlife sightseeing experiences. Blink and you'll miss it.