Dominica's Boiling Lake is situated in the Morne Trois Pitons National Park - Dominica's World Heritage site. It is a flooded fumarole 6.5 miles (10.5 km) east of Roseau, Dominica. It is filled with bubbling greyish-blue water that is usually enveloped in a cloud of vapour. The lake is approximately 200 ft (60 m) across.
The first recorded sighting of the lake was in 1870 by Mr. Watt and Dr. Nicholls, two Englishmen working in Dominica at that time. In 1875, Mr. H. Prestoe, a government botanist, and Dr. Nicholls were commissioned to investigate this natural phenomenon. They measured the water temperature and found it to range from 180 to 197 degrees Fahrenheit (82 to 91.5 Celsius) along the edges, but could not measure the temperature at the centre where the lake is actively boiling. They recorded the depth to be greater than 195 ft (59 m).
Periodically, there have been fluctuations in the level and activity of the lake. In the 1870s it was deep, after a phreatic eruption nearby, in 1880 the lake disappeared and formed a fountain of hot water and steam. Another phreatic eruption lowered the lake level by some 10 m from December 2004 to April 2005, later the lake level rose again.
There is no road leading directly to the lake. It is approximately a 13 kilometer hike to the lake from the nearest road, passing sulfur springs, over mountains and through gorges along the way.
On July 6, 2007, adventure-film maker George Kourounis became the first person to ever cross the boiling lake from above, suspended by ropes over the most violently boiling section. This event was filmed for the TV series Angry Planet.