 Its summit is 2490 feet (about 760m) above sea level.Fan Hir is separated from its higher neighbour to the north-west, Fan Brycheiniog (2633 feet or 802 metres) by a col known as Bwlch Giedd, where a path rises from Llyn y Fan Fawr via a stone staircase.The hill is drained to east and north by streams which make their way into the River Tawe.