Blog Post

Create Your Own Cave in a Cup and observe how water flows through these Ozarks hills

Create Your Own Cave in a Cup

Create your own cave. As water flows beneath the Earth's surface it dissolves and erodes the rock, forming the cavities that become caves.

The slow process that left the Ozarks honeycombed with springs, caves, and sinkholes is happening all the time. It never comes to an end. As soon as one is complete, another has started

The list of factors needed for the perfect cave-creating environment is short. You need plenty of soluble rock, like all the limestone found in the Ozarks. Add plenty of rain or melting snow to supply the groundwater. Finally, since water flows downhill, you need uneven land (hills/mountains). And there's no shortage of hilly terrain in the Ozarks.

  • Soluble rock is a rock that can be dissolved or broken down by water
  • Groundwater is water that has soaked into the Earth’s surface finding its way into voids and fractures in the soil and rock

To create your own cave at home, here's a list of supplies

  • Clear plastic cup
  • Sand
  • Waterproof wood glue
  • Something to puncture the cup to allow water to escape (a nail works well)
  • A large basin to catch the run-off water
  • Warm water

Recreating the layers of the earth in a cup

Cave in a Cup Activity

  1. Place a layer of sand at the bottom of your cup about ¾” thick.
  2. On top of the sand, place a layer of sugar cubes (as many that will fit).
  3. Completely cover the sugar cubes with waterproof wood glue (enough glue to run along the sides of the sugar cubes).
  4. Add another layer of sand on top of the glue.
  5. Repeat the process until you have multiple layers of sand, sugar cubes and glue. As you build up your layers, stop about an inch to a half inch from the top of the cup. Place a final layer of sand on top of the last layer of glue.
  6. Let dry (this may take 1-2 days).
  7. Poke 1 or 2 holes on the side of the cup near the very bottom where you see sugar cubes.
  8. Place your completed cave in a cup in a lager container to catch the flow of water and then begin to slowly pour warm water onto that top layer of sand in the cup. Let the water percolate through the layers to find the holes near the bottom. Continue to pour warm water until all of the sugar cubes dissolve, leaving behind the hardened glue and sand.

Adding warm water to start the cave creation process inside a cup

The process you are witnessing within your cup occurs beneath the surface of the Ozarks constantly

As water flows beneath the Earth's surface, it washes away bits of the limestone beneath the ground. The groundwater chemically and physically eats away at the limestone. This slow erosion of rock over time forms the openings that eventually become caves. Water passes through voids in the limestone underlain in the Ozarks, taking small pieces of rock with it. That action also allows for the production of all the cave formations we love, such as stalactites, stalagmites, columns and many others.

You can create your own cave in a cup pretty quickly, but the caves found in the Ozarks are really old... we just don't know how old

It is very difficult to determine the age of a cave because the rates of water flow and chemical activity vary widely throughout time. The caves of the Ozarks are very old, but we really don't know how old. Unless it's interrupted, this process will continue throughout the life of the cave, until the cave finally deteriorates and is destroyed by the same natural processes that created it. Sometimes there are remnants - a natural bridge, a canyon-like valley or a tunnel perhaps - to indicate that a cave was once there.

Create your own cave in a cup

The list of ingredients for making a cave is short

You need plenty of limestone, a rock that can be dissolved in groundwater. Add plenty of rain to supply the groundwater. Finally, since water flows downhill, you need what geologist call "relief" - uneven land.

For untold ages, the same processes that created Fantastic Caverns also created the nearly 7,500 plus other caves in “the Show Me State”. It’s no wonder Missouri is also known as “the Cave State.” The karst areas of the Ozarks - southern Missouri, northern Arkansas and parts of eastern Oklahoma and Kansas - are perfect for this cave building process to take place.

Water moving through the auditorium at Fantastic Caverns

About the Author

Hubert Heck
Hubert Heck

Director of Marketing

Hubert Heck is the Director of Marketing for Fantastic Caverns