Wakae no Shima, or Wakae Island, is the extant site of the oldest artificial harbor in Japan. During the Kamakura period (1185–1333), the coastline at Zaimokuza was teeming with ships coming to Kamakura from all over the country, but shallow waters extending far from shore made it inconvenient for ships to load and unload their cargo. Moreover, the shallow waters also led to many of these ships becoming shipwrecked. To solve the issue, priest Oamidabutsu (dates unknown) constructed an island with Izu stone and other materials with the cooperation of shogunate regent Hojo Yasutoki (1183–1242). At low tide, you can walk out over the rocks.