Door to Hell, Darvaza Gas Crater

The Darvaza gas crater sits in the Karakum Desert of Turkmenistan, near the small village of Darvaza about 260 kilometers (160 miles) north of the capital, Ashgabat. Officially named the Shining of Karakum but known worldwide as the Door to Hell, the crater measures roughly 60 to 70 meters (200 to 230 feet) across and about 30 meters (98 feet) deep, with flames fed by a natural gas field in the collapsed cavern below.

The most widely told account of its origin places the collapse in 1971, when drilling punctured an underground gas cavern and the ground gave way beneath the rig. Engineers are said to have set the escaping gas alight to stop poisonous fumes from spreading, expecting the fire to burn itself out within weeks. Instead it kept burning for decades, turning a drilling accident into one of Turkmenistan's most recognizable landmarks and a draw for travelers willing to make the long, visa-restricted trip into the desert. In recent years, Turkmen authorities have worked to reduce the crater's output, and reports describe the flames diminishing substantially as nearby wells capture methane from the field — a contrast with the fully ablaze crater shown in this puzzle, which reflects how the Door to Hell has looked for most of its history.

In this puzzle, the dark band of desert sky and silhouetted hills at the top assemble first as flat, low-detail pieces, and the brightest white-orange flame clusters near the crater floor give a second easy anchor. The wide field of glowing, broken rock across the crater walls is the slower stretch, solved by matching small shifts of orange, black, and ember-white.