Basalt Columns, Caves & Fossil Leaf Beds

The Ardtun Basalt Columns are found along the dramatic coastal cliffs near Ardtun on the Ross of Mull. These impressive geological formations, characterized by their distinct columnar structures, were created as ancient lava flows cooled and fractured into polygonal pillars. While perhaps not as singularly famous as Fingal’s Cave, this area is of immense geological significance, offering a unique insight into Mull’s volcanic past and even prehistoric life. The caves here are often smaller sea caves formed directly within these columnar basalt cliffs, showcasing the same impressive hexagonal formations as Staffa, though often in a more eroded or “twisted” form.

What makes the Ardtun area truly special is the presence of the Ardtun Fossil Leaf Beds. These beds, sandwiched between layers of the basalt columns and lava, contain remarkably well-preserved fossilised leaves, foliage, fruit, and stems from ancient trees such as oak, hazel, and plain trees, as well as conifers. These unique fossils, estimated to be about 58 million years old, are found in three differing layers of sediments and provide crucial evidence of the subtropical climate and lush vegetation that existed in this region during the Palaeocene epoch, before the opening of the Atlantic Ocean. The area is designated an Area of Special Scientific Interest (SSSI) for its palaeobotanical importance, being the only place in the UK to yield these specific types of fossils.

Visitors can explore the coastal path at Ardtun, observing the striking columnar basalt formations and locating the fossil leaf beds in a shallow open gully. Access to the site involves traversing pathless moorland and coastline, which can be very boggy and slippery in parts, making waterproof boots highly recommended. The caves themselves are generally less accessible than Fingal’s Cave, often requiring more adventurous scrambling over rocks. However, the profound geological context, the presence of ancient fossils, and the stunning coastal scenery make the Ardtun Basalt Caves a significant site for anyone with an interest in geology, palaeontology, or simply the raw beauty of Mull’s coastline.