Nea Kameni is sometimes called the "Santorini Volcano." The island's rocky crater continues to rumble and puff out steam. Boat tours depart from the town of Oia, the Old Port of Fira, or the Athinios Port on Santorini's main island. Once on the island, you can hike up to the crater's rim and take in the views across lava fields to Greece's Aegean Sea.
Volcano tours may also stop on Thirasia, the second-largest island in the archipelago, and at the volcano's hot springs on Palea Kameni, where boats moor at Erinia and you can swim to the springs beneath the tiny church of Agios Nikolaos. Santorini volcano and hot springs tours get big crowds in high season, so opt for a small-group guided tour or catamaran tour if you would prefer a more personal experience.