Cruach Ardrain is a Munro mountain in the Breadalbane region of the Scottish Highlands, with a height of 1,046 metres (3,432 feet).

The southern ridge links to the adjoining Munro of Beinn Tulaichean which lies two kilometres away across a high col at 825 metres.

The head of Coire Ardrain contains Y Gully, a scrambler's route which leads directly to the summit and gives a fine ice climb (grade 1) in winter.

Y Gully made the mountain popular with the early pioneers who enjoyed a challenging route to any summit.

[8] Another well known ice climb on the mountain is Hollow Gully which is located on the rocky spur of Stob Glas (c.820 metres) which lies 1 km south-southwest of the main summit.

[9] Cruach Ardrain currently has one Munro “Top” located on its slopes, the 959 metre Stob Garbh (Rough Peak) situated 1 km away on the northern ridge.

The rule is a simple formula for estimating walking time taking into account not just distance but also height to be ascended.