Mega Cavern facts for kids

The Mega Cavern is a huge underground space in Louisville, Kentucky. It used to be a limestone mine, where workers dug out rocks. This amazing place stretches beneath parts of the Watterson Expressway and the Louisville Zoo. Because of its strong support structures, it's actually considered a building. In fact, it's the largest building in all of Kentucky! Today, the Mega Cavern is used for many things. It's a place for businesses, storage, and even recycling. It's also a popular spot for visitors, offering fun activities like tram tours, zipline adventures, a ropes course, and a big holiday lights show every year. It even used to have an underground mountain bike park!

What is the Mega Cavern?

The Mega Cavern is a massive underground structure in Louisville, Kentucky. It covers about 4,000,000 square feet (371,612 square meters). That's like 70 football fields! This huge space is located about 75 to 100 feet (23-30 meters) underground. It runs beneath parts of the Watterson Expressway and the Louisville Zoo. Because of its strong walls and ceilings, it's officially called a building. It holds the record as the biggest building in Kentucky.

How did the Mega Cavern start?

From a mine to a modern space

The Mega Cavern began as a big limestone quarry. It was first known as Louisville Crushed Stone. For over 42 years in the middle of the 20th century, miners used explosives to blast out rock. They were digging for limestone, a type of rock used in many things, like building materials.

In 1989, some smart investors bought the mine. They saw that this huge underground area could be used for new purposes. They wanted to turn part of it into a secure storage facility. This new facility would also be good for the environment.

Making the cavern new again

A business park underground

After all the limestone was mined, the property was bought by Jim Lowry, Tom Tyler, and Don Tyler in 1989. Their goal was to create a "high-security business park" inside the cavern. By February 2015, the mine was home to 12 different businesses. These businesses used about 700,000 square feet (65,032 square meters) of the underground space.

Storing things safely

The Mega Cavern is a great place for storage because its temperature stays steady. It's usually around 50-60°F (10-16°C) and has stable humidity. To make it useful for storage, parts of the mine's floor were raised. This was done by filling them with recycled materials. A special fire-resistant safety tunnel was also built. This tunnel acts as an emergency exit. Many different items are stored in rooms throughout the mine. You might find anything from road salt and vehicles to pretzels and even amusement park rides!

Fun for visitors

In 2009, the Mega Cavern started offering tours. Visitors could ride in a Jeep to see the areas where the floor had been raised. Around Christmas time, the mine hosts "Lights Under Louisville." During this event, people can drive through the cavern and enjoy thousands of lighted holiday decorations. It's the biggest underground holiday light display in the world! A few years later, a zipline tour and a ropes course were added. These activities let visitors explore the cavern in exciting new ways.

An underground mountain bike park opened in February 2015. It attracted attention from all over the world. The park was designed for riders of all skill levels, including families. It took over three months to build. With 45 trails in 350,000 square feet (32,516 square meters) of the mine, it was the world's largest indoor bicycle park. The trails stretched for 12 miles (19 kilometers), with over 5 miles (8 kilometers) connected together. They included different types of paths like "jump lines, pump tracks, dual slalom, BMX, cross country, and singletrack." Signs helped riders know how difficult each trail was. The bike park is now permanently closed.

More to explore

• List of attractions and events in the Louisville metropolitan area
• SubTropolis, a similar but much larger mine in Kansas City, Missouri