About 1.5 kilometers from Stromboli's northeastern edge lies a sea stack known as Strombolicchio, believed to have been produced by volcanic activity. Sharp cliffs that plunge straight into the water give the island its distinctive appearance. The mountain's slopes are of great ecological significance since they shelter numerous endangered species of plants and animals.

The underwater walls descend roughly 50 meters to a sandy floor and are inhabited by encrusting algae, sponges, marine annelids, bryozoans, and gorgonians. As a bonus, the Italian Navy owns and operates a lighthouse atop Strombolicchio, adding another attraction to the island.