Classroom lesson · Lucayan Caves · 🇧🇸 Bahamas

Lucayan Caves

Ancient caves full of fossils and underground lakes

Photo · Wikimedia Commons

What is it?

On the island of Grand Bahama there is a special national park called Lucayan National Park, which contains one of the longest known underwater cave systems in the world. The caves stretch for miles underground and are home to beautiful rock formations, fossil bones, and crystal-clear underground rivers.

Tell me more

The Lucayan caves were carved out of the soft limestone rock over millions of years as rainwater slowly dissolved pathways through the stone. The result is a labyrinth of tunnels, caverns, and underground lakes that explorers began mapping in the twentieth century. Scientists have found bones of animals and humans inside that help us understand the ancient history of the islands.

Inside the caves, stalactites hang from the ceiling like stone icicles, and stalagmites grow up from the floor. They form when minerals in dripping water build up grain by grain over thousands of years. A stalactite the size of a pencil might be a hundred years old — they grow incredibly slowly.

The park above the caves is also beautiful. Mangrove forests grow at the edges of the water, creating a tangle of roots that act like a nursery for young fish. Visitors can walk along wooden boardwalks through the mangroves and look down into the glassy water of the cave openings below.

The caves are named after the Lucayan people, who were the first people to live in the Bahamas, long before any Europeans arrived. The park protects the caves and the forest above them so that everyone — fish, birds, and people — can share this remarkable underground treasure.

In the classroom

Walk your class through this in 15 minutes.

Talk together

Discussion prompts

  1. 01Stalactites grow about one centimetre per century. How long would a one-metre stalactite take to form?
  2. 02Why might scientists be excited to find old bones inside a cave?
  3. 03Mangrove roots act as a nursery for fish. Can you think of other examples in nature where one creature's home helps another creature?
  4. 04If you discovered a new cave, what would you name it and why?
Try this

Classroom activity

Make a stalactite and stalagmite model using clay or salt dough. Hang your stalactite from a pencil stretched across two cups, and build your stalagmite on a piece of card below it. Label each one and write one fact about how they form.