Basalt Caves & Fossil Leaf Beds

The Ardtun Basalt Caves are found along the dramatic coastal cliffs near Ardtun on the Ross of Mull. 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 within the 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 basalt lava, contain remarkably well-preserved fossilised leaves from ancient trees such as oak, hazel, and plain trees, as well as conifers. These fossils, dating back approximately 58 million years, 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 and the extensive volcanic eruptions. The area is designated a Site of Special Scientific Interest (SSSI) for its palaeobotanical importance.

Visitors can explore the coastal path at Ardtun, observing the columnar basalt formations and, with careful searching and an understanding of the site, locate the fossil leaf beds. The caves themselves are generally less accessible than Fingal’s Cave, often requiring more adventurous scrambling over slippery rocks. However, the 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.