The Door to Hell is a natural gas field in Derweze (also spelled Darvaza, meaning "gate"), Ahal Province, Turkmenistan. The Door to Hell is noted for its natural gas firing which has been burning continuously since 1971, fed by the rich natural gas deposits in the area. The pungent smell of burning sulfur pervades the area for some distance.

The field is situated near the Derweze village. It is in the middle of the Karakum Desert, about 260 kilometres (160 mi) north from Ashgabat. The gas reserve found here is one of the largest in the world. The name, "Door to Hell", was given to the field by the locals, referring to the fire, boiling mud and orange flames in Derweze's large crater of 70 metres (230 ft). The hot spots range over an area of 60 metres (200 ft) and to a depth of 20 metres (66 ft).

The site was identified by Soviet scientists in 1971 It was thought to be a substantial oil field site. The scientists set up a drilling rig and camp near by, and started drilling operations to assess the quantity of gas reserve available at the site. As the Soviets were pleased with the success of finding the gas resources, they started storing the gas. The ground beneath the drilling rig and camp collapsed into a wide crater and disappeared. No lives were lost in the incident. However, large quantities of methane gas came out, creating huge environmental problems and causing immense harm to the people of the villages, which resulted in some deaths.

Fearing the release of poisonous gases from the cavern, the scientists decided to burn it off. Environmentally, gas firing is the next best solution when the circumstances are such that it cannot be extracted for use. Methane gas released into the atmosphere is a dangerous greenhouse gas whose potential for global warming is high At that time, expectations were that the gas would burn within days, but it is still burning, decades after it was set on fire.