The underwater of the Lastovo archipelago is rich in flora and fauna, as well as many archaeological sites. Hidden passages and caves, and the diversity of the underwater are perfect for divers. The most attractive diving sites are Seka Drašan on the north-eastern side of the island, the Petrovac shallow with a protected underwater archaeological site, the Bijelac islet, which hides the underwater passage through the island, the Tajan islet, with an underwater cave, and the Struga cliff, with interesting flora and cliffs up to 80 m deep.