The volcano cones that form this archipelago are part of the Mid-Atlantic ridge, a vast undersea mountain range that meanders between the poles. The islands rise at the junction of three tectonic plates, and when these shift, molten rock boils up to fill the cracks, sometimes sending mild tremors through the chain. It is this volcanism that gives the islands their compelling landscape of collapsed craters and Fuji-shaped peaks.
Plotting an itinerary around crater lakes, sulfur springs, and lava caves, we divide a weeklong trip between the most populated islands, São Miguel and Terceira.
And so, on São Miguel, we drive from the airport directly to Furnas, a spa-resort village in a "furnace" of volcanic hot springs. A popular tourist destination in a valley ringed by mountains, Furnas is home to an Art Deco hotel, the Terra Nostra Garden, which overlooks a 150-year-old garden-turned-public park. The hotel, painted mustard yellow, stands on part of a former estate settled in the 18th century.
The lavish garden contains water in all its forms - streams, falls, ponds, and a lagoon shaded by old trees. Garden rooms, screened by curving paths and high hedges, hold collections of camellias and azaleas, rhododendrons and cycads - startling plants that look like small palms sprouting fernlike fronds.
At the garden entrance is the hotel's sulfur spa, a pool of opaque, rust-colored water with eggy-smelling steam rising from the surface. It's not immediately appealing, but after watching other guests pad back and forth in orange-smudged bathrobes, we take the plunge. The water, thick and buoyant, enfolds the body in a liquid blanket.
Signs of the Azores' volcanic origins are everywhere: in the pastures that tilt away from the road at crazy angles, the crumbly pumice underfoot, and the abrupt slopes. The Furnas Caldera, a collapsed volcano crater above the valley, sends up plumes of steam near the lake. It is dotted with kettle-sized pits boiling with steam.
