Introduction to the Heijo Palace Ruins: Heijo Palace is a capital ruins built after the capital was moved to Heijo in the Nara Period. It is a United Nations World Heritage Site. Nara was designated as the capital of Japan in 710. It was formerly known as Heijo-kyo. It was the first true capital of Japan and has a longer history than Kyoto. In the next 74 years, Heijo-kyo prospered and prospered. The ruins of Heijo Palace are The oldest witness to this history.