The Boiling Lake is a flooded fumarole located in Morne Trois Pitons National Park, a World Heritage Site on the island of Dominica. The lake, located 6.5 miles east of Dominica's capital Roseau, is filled with bubbling greyish-blue water that is usually enveloped in a cloud of vapour. The Boiling Lake is approximately 200 to 250 feet across and is the secon…The Boiling Lake is a flooded fumarole located in Morne Trois Pitons National Park, a World Heritage Site on the island of Dominica. The lake, located 6.5 miles east of Dominica's capital Roseau, is filled with bubbling greyish-blue water that is usually enveloped in a cloud of vapour. The Boiling Lake is approximately 200 to 250 feet across and is the second-largest hot lake in the world after Frying Pan Lake, located in Waimangu Valley near Rotorua, New Zealand.