You smell Bass Rock before you see it: a sharp, ammoniac reek of guano that cuts through the salt of the sea air like a chemical alarm, growing stronger as the boat approaches the white lump of volcanic rock that sits in the Firth of Forth, 2 km off the coast of North Berwick, 30 km east of Edinburgh. The white is not rock, it is birds. One hundred and fifty thousand northern gannets, the largest colony on a single island anywhere on Earth, covering every ledge, every crevice, and every square inch of the rock’s 107-metre summit in a seething, screaming, shrieking mass of feathers, beaks, and the accumulated excrement of millennia. The noise, 150,000 gannets calling, is a wall of sound that hits you like a physical force, the air thick with birds circling the rock in a tornado of white, and the experience of floating beneath this cathedral of seabirds, the sky white with wings, the sea thrashing with the birds diving for fish at 60 mph (the gannet folds its wings and drops like a javelin, a perfect hydrodynamic missile, hitting the water with a splash that sends spray high into the air), is one of the most extraordinary wildlife spectacles in Europe. Here is a guide to Bass Rock.

Quick Facts: Bass Rock

• The gannet colony, the largest on Earth: Bass Rock holds 10% of the world’s northern gannets. The colony has grown from 4,000 pairs in the 1960s to over 75,000 pairs today, a conservation success story that has transformed the rock from a grey volcanic plug into a white pyramid of birds visible from the Edinburgh skyline on a clear day. The gannets arrive in February–March, lay their eggs in April–May, and the chicks fledge in September–October before the entire colony departs for the winter, to the coast of West Africa, 3,000 miles south, the young birds following an ancient migratory route encoded in their DNA. A gannet lives for up to 35 years, mates for life, and returns to the same nest, the same square foot of rock, year after year. The nests are built of seaweed, grass, and guano, packed into the ledges with a density that seems impossible, the birds sitting bill-to-bill in a truce of mutual proximity. The colony is healthy, noisy, and one of the most important seabird sites in the North Atlantic
• How to visit, the essential boat trip: The Scottish Seabird Centre in North Berwick (~30 min by train from Edinburgh Waverley) runs boat trips around Bass Rock from April to September. The boats circle the rock (you cannot land, the rock is too steep, the birds too dense, and the guano too deep), and the 30–45 minutes you spend floating beneath the colony, the birds diving into the sea around the boat, the gannets flying overhead with wingspans of 1.8 metres (six feet, the wingspan of a tall man), the noise and the smell and the sheer, overwhelming abundance of life, is one of the most memorable wildlife experiences in the UK. Price: ~£28 (adult). Book ahead, the trips are popular and the boats are small (12 passengers on the RIB, the rigid inflatable boat, the faster, wetter, and much more exciting option). Alternative: the Seafari (a high-speed RIB, you get closer to the rock, the ride is more exhilarating, and you are far more likely to get soaked. ~£39). Essential gear: a waterproof jacket (the spray is real), binoculars (the birds are everywhere, but the detail, the gannet’s blue eyes, the delicate grey-blue bill, the golden-yellow head that gives the species its Latin name Morus bassanus, is best appreciated through lenses), and a hat (the guano is, technically, airborne). The seabird centre in North Berwick, the interactive exhibits, the live cameras on the rock (you can control a camera remotely to zoom in on individual nests), and the view of the rock from the observation deck, is an excellent complement. Entry: ~£12. More UK →
• The history, a prison, a hermitage, and a lighthouse: Bass Rock has been a prison (the 17th-century Covenanters, Scottish Presbyterians, were held in a dungeon on the rock, the conditions brutal, the prisoners surviving on seabird eggs and the occasional mercy of the gannets), a hermitage (the 7th-century Saint Baldred lived on the rock, his cell a cave, his companions the birds), and a lighthouse (the 1902 Stevenson lighthouse, one of the last built by the Lighthouse Stevensons, the family of Robert Louis Stevenson, automated in 1988, the beam still visible from North Berwick on a dark night). The ruins of the chapel (dedicated to Saint Baldred) and the prison walls are visible from the boat, the history adding a layer of human suffering to the natural spectacle