There is a lake underneath Bonne Terre, Missouri, and it has a locomotive parked in it.
The town sits on top of a lead mine that ran from 1864 until the early 1960s. The St. Joe Lead Company started building it in 1864, the first shaft went down in 1869, and by the turn of the century this was the foremost lead producer in the world. It was worked room and pillar, meaning columns of untouched rock were left standing to hold the ceiling, across five levels shaped roughly like a cone. When the lead price fell and the geology showed the richest ore was already out, the company closed it and switched off the pumps.
Rain and spring water did the rest. The lowest three levels are now fully flooded, the second is partly under, and only the top level is dry. What that leaves gets billed as the largest man made cavern in the world, and the water in it as the largest underground artificial lake.
Doug and Cathy Goergens, who ran West End Diving in Bridgeton, bought the mine in 1980 and opened it for scuba the year after. The water is exceptionally clear, with sight lines often reaching 50 metres, and half a million watts of floodlighting is aimed into it. Divers pass abandoned mining equipment on the floor, including a mine locomotive about 15 metres long, left where it stopped.
In 1983 the crew of Jacques Cousteau's Calypso came to explore it for a documentary. The mine had been added to the National Register of Historic Places in 1974.
You do not have to dive. Walking tours follow the Old Mule Trail through the dry upper level and take about an hour, and pontoon boats run out onto the lake. The surface tour takes in a mining museum, a barbershop and a post office. It holds a steady 17 degrees Celsius down there whatever the season.
The water surface sits about 50 metres below the streets of the town.
Other places on the map within a couple of hours.
