Etna is an enigma; even its height is never certain as it changes with each new eruption. But at more than 3,000 meters, it rules the skyline with its often-smoking cone.
Volcanic vents, fumaroles, hot springs, and lava flows add to its changing landscape, much of which you can explore (although not too close to the central crater) on foot or in all-terrain vehicles designed for traction in the volcanic surface.
Roads lead to the base of cable cars, which will take you to the 2,500-meter point, an easy day trip from Catania or Taormina. In the winter, you can ski near the summit.