Bass Rock, Scotland, 17th century artwork. This island, in the Firth of Forth, Scotland, has been home to a large colony of northern gannets (Morus bassanus) for centuries, with an estimated 150,000 breeding here. The gannets are seen flying around the island, and sailing ships are also seen. The island itself is volcanic with steep cliffs. The highest point is 107 metres above sea level. The island was initially inhabited by Christian hermits. Later, a castle and fortress was built (shown here), often used as a prison. The fortress was destroyed in 1701. Artwork published in 1693.