The most cryptic and unique trip I ever had was to Turkmenistan, a country in Central Asia bordered by the Caspian Sea and largely covered by the Karakum Desert. It’s known for archaeological ruins including those at Nisa and Merv, major stops along the ancient trade route the Silk Road.
You will be amazed to know that Natural Gas is so abundant in Turkmenistan that it is supplied free of charge to all households. Matches, however, are not free - so the people of Turkmenistan never extinguish their stoves etc, they just keep them burning, all day, all night.
Coming back to the topic, The Door to Hell. It actually is a place. One of the most amazing sights on earth - the Darvaza Gas Crater. Under Soviet times, there was a gas mining project that went wrong, the apparatus collapsed and left a huge crater, about the size of a football field. When the debris was removed, they noticed that gas was leaking from the ground. Geologists suggested they set fire to it, because the gas would burn out in a few days. Nearly 44 years later...it's still on fire. It's also known as the Gates to Hell or the Crater of Fire. It's a day's drive into the desert to get there, and my word is it's worth the trip. Have a look for yourself: