Surrounded to the north, east, and west by hills and to the south by the open water of Sagami Bay, Kamakura is a natural fortress. Before the construction of several tunnels and modern roads that now connect it to Fujisawa, Ofuna (ja) and Zushi, on land it could be entered only through narrow artificial passes, among which the seven most important were called , a name sometimes translated as "Kamakura's Seven Mouths". The natural fortification made Kamakura an easily defensible stronghold.