These Sicily boat tours, bookable on Airbnb, include visits to secluded swimming coves and onboard Aperol spritzes. ... In the afternoon, we had a chance to swim through caves on Levanzo, ...

ESA astronaut Luca Parmitano launching a drone during the CAVES-X1 expedition in a cave system in Italy, May 2017. Credit: ESA, Natalino Russo www.natalinorusso.it, CC BY-SA 3.0 IGO ...