Geology of Edinburgh course: Pentland Hills walk

Welcome to the Geology of Edinburgh course, a combination of walks and online learning in October and November 2025. You are welcome to attend the whole course, or individual sessions. Programme & booking information – geowalks.scot/geology-courses/.

Geology of Edinburgh course: Pentland Hills walk

The rocks of the Pentland Hills were formed during volcanic eruptions around 400 million years ago. This low-level short walk takes us into the heart of the Pentlands and through a range of rock types and landforms that show how the hills have been constructed and eroded.

THE ROCKS: We will explore a variety of igneous rocks, formed by volcanic activity during the early Devonian period, around 410 million years ago. The rocks include andesite and microgranite, and they have been affected by a long history of deformation and uplift since they formed. In the centre of the Pentlands, we also get a glimpse beneath the volcanoes, to much older rocks formed on a vanished ocean floor.

THE WALK: The walk starts at Red Moss, and climbs towards Bavelaw to take a low-level route through a glacial drainage channel to the south of Black Hill. We then retrace our steps a short distance and pick up a path along the side of the Black Hill, around the Threipmuir Reservoir and back to the start. I have classified this as a Moderate Walk, not always on paths, it may be rough or slippery underfoot at times. It may be wet, windy or cold. Come equipped with strong footwear and waterproof clothing.  Duration 3 hours, distance 9 km.

MEETING POINT & ROUTE: Meet at the Red Moss Car Park, follow Mansfield Road south of Balerno. Grid reference NT 166 638| Nearest Postcode: EH14 7JT | What3Words: multiples.still.ages | Route Map.