This historic site holds the ruins of Tomyo-do, which stood at the entrance to Uraga Harbour in the Edo period, and the surrounding beach. The Tomyo-do was a two-story building built on a stone wall foundation, with a watchman's hut below and a copper lamp dish 36.4 cm in diameter and 12.2 cm deep above. It is said to have been lit by a hundred stands of lamps and a square of rapeseed oil per night, with the light reaching four nautical miles (7.4 km). Expenses were covered by the Tokugawa Shogunate until 1690 (Genroku 3), but from 1690 (Genroku 4), the dried sardine wholesalers in Higashiuraga began to bear the costs. The system remained active for about 220 years until it was abolished in April 1872.