Even with your eyes closed, you’ll know you’ve reached Mount Soufriere, the island’s volcano, because the sulphur smell (remember rotten eggs from chemistry class?) pervades the air. Although the last major eruption was in 1766, the semi-active volcano still spews hydrogen sulfide. For kids who’ve never witnessed geothermal activity, the bubbling mud and steaming fumaroles are eye-opening. Start by watching the video at the Sulphur Springs museum. Then, go to the overlook to view a part of the caldera, created when the volcanic cone collapsed nearly 40,000 years ago. Encompassing much more than the ash you see, the more than seven-square-mile caldera takes in the nearby town of Soufriere, as well as the visitor parking lots. Hence, the term “drive-in volcano.” You can slather yourselves with the reputedly healing, dark volcanic mud and rinse off in a “pool” — for an extra fee, of course. The entrance to this separate facility is near the ticket booth and vendors’ row.