Tens of sea caves and other coastal karst landforms are to be found along the limestone coast of the Maltese Islands. Most of the sea caves develop around the present-day sea level, such as Blue Grotto, which is one of the widest and most spectacular sea cave on the islands. The Blue Grotto karst system is composed by partially submerged chambers, sea arches, gorges and small-scale landforms, such as coastal notches, and speleothems. Such landforms developed at the northwestern side of Wied Babu, in a half a kilometer wide bay near Żurrieq. This chapter presents the results of a detailed geomorphological survey of these coastal and karst landforms and discusses the origin and development of the studied landforms. The close relation with the sea level suggests that the system is partly related to former enlargement of dissolutionally widened karst voids and partly related to present-day marine processes, such as waves, and subaerial processes, including rock collapse. Although most of the species recorded from the environs of Filfla are common elsewhere around the Maltese Islands, in general, the recorded biotopes exhibit high species richness values, which is indicative of a low degree of anthropogenic pressure being exerted on the site.
