Santorini’s flooded caldera hogs the headlines, but the smoldering crater on Nisyros is equally dramatic. In fact, this entire Dodecanese island is an active volcano, with a 2.5-mile caldera surrounded by several smaller craters. Although the volcano hasn’t erupted since 1888, hot puffs of steam hiss as you tread gingerly across Stefanos's crackling yellow surface. If you can’t stand the sulfurous stink, the adorable village of Nikia dangling above the volcano offers excellent aerial photo opportunities. The village school has been converted into the Volcanological Museum, with 3-D models and videos explaining the big bang that created Nisyros 24,000 years ago. Afterward, stop at Nikolas’s kafenio in Porta, a miniature pebbled piazza painted with geometric patterns, for an ouzo meze.