The Straits of Ha'zen was a location on Vulcan. Bordering on the west of the province of Gol, the straits were a shallow channel of water between Na'nam and the island continent of Xir'tan. The waters were noted as being extremely difficult to navigate due to the constant shifting of the tectonic plates beneath them. (Last Unicorn RPG module: The Way of Kolinahr: The Vulcans)