It's called Sulphur Springs for reasons that quickly become obvious.
Time: 45-60 minutes. Difficulty: 1-2. The walk is a short one. You can see the active area from the car park.
Trailhead: Near Soufriere, a turnoff on the road to Vieux Fort.
The sign near Soufriere advertising "the world's only drive-in volcano" marks the entrance to what are perhaps the most accessible sulfur fields anywhere in the Caribbean.
The presence of sulphur is often strong enough to discolor silver jewelry. The rotten egg/onion odor is memorable. A kiosk at the entrance (small admission fee) will pair you with a guide, whether you need/want one or not.
This was a volcano about 13km in diameter until 40,000 years ago when it collapsed in on itself. Theoretically it could erupt with hot ash and lava, not just gases.
Mineral deposits have left the earth colored with orange, green, yellow and purple streaks.
The bubbling mud pots bordered by steam vents jetting as high as 50 feet are impressive. At one time it was possible to walk among this field in the remnant of a volcanic crater, but after a few hikers stepped through the earth crust and were almost seriously hurt, everyone was confined to a boardwalk.
You can still get close enough to see everything clearly if you take binoculars and a telephoto lens. This is a hot, open place; far from what you would call beautiful, compared to the high surrounding vegetation, but nonetheless fascinating.