An Caisteal, which qualifies as a Munro, is located in a popular area for hill walking within a group of seven Munros and fourteen tops which stand on the eastern side of Glen Falloch in the Loch Lomond and the Trossachs National Park. The mountain reaches a height of 995 metres (3,264 feet) and is usually climbed in conjunction with the neighbouring Munro of Beinn a' Chroin to which it is connected by a high col to the south east. The mountains name translates from the Gaelic as the castle and is believed to refer to the prominent castellated rocks close to the mountain's summit which serve as an easy way of identifying the mountain from a distance.