Double Gate is closer to the SW corner of the Temple Mount. The triple arches, closer to the SE corner of the Temple Mount, are called Triple Gate. Both sets of gates are currently below ground level of the Mount. This was not always the case. Before the destruction of Herod's Temple, (which existed from 16 BCE - 70 CE) the ground level of the southern section of the Temple Mount (below the Al Aqsa Mosque) was approximately 30-40 feet lower than it is today. Temple Mount expert, Norma Robertson, details this research in Locating Solomon's Temple.