When drilling into the ground, it’s always a good idea to know exactly what is below you.

An incredible and strange spectacle, the Gates of Hell is only one example of the kinds of disasters that can happen when you dig blindly.

On November 20, 1980 in Erath, Louisiana the Wison Brothers were drilling through the bottom of Lake Peigneur when their 14 inch drill bit became stuck and the entire drilling operation began shaking. They quickly abandoned the platform only to watch the huge rig disappear beneath the water as the entire lake turned into a massive vortex, sucking big-rig trucks, barges, and lakeside vacation houses into it. Unbeknownst to the workers, the drill bit had accidentally punctured a slat mine below and the shallow freshwater lake had been permanently turned into a salty deepwater lake.

Across the world, a similar disaster happened in Sidoarjo, East Java in 2006. A gas drilling operation triggered a “mud volcano,” killing 13 and unleashing a torrent of hot mud that continues to flow. The mud flows up from the ground at an estimated 50,000 cubic meters—a dozen Olympic swimming pools—each day. It now covers more than 25 square kilometers and is expected to continue flowing for up to another 30 years.

While Sidoarjo and Lake Peigneur were disastrous, a disaster can offer unexpected beauty. Fly Geyser in Gerlach, Nevada was created when a geothermal company drilled into the desert looking to tap into the hot springs trapped below. The water they found was not hot enough for their needs and they capped the drilling site. The cap ruptured and the hot water began geysering out of the ground. Over the last 40 years, the minerals from the water have been deposited onto the desert surface creating a strange and alien mound.

Whether the results are strangely lovely, as in the case of Fly Geyser and the Gates of Hell, or sheer disaster as with Sidoarjo and Lake Peigneur, the lesson remains the same: Look before you start tearing into the Earth’s crust.