Imagine you’re crawling in a cave underground. It’s dark and chilly. You flip on your flashlight and can’t believe your eyes.
Everywhere you look, giant crystals cover the walls and the floor. Welcome to the Pulpí Geode!
JORGE GUERRERO/AFP/Getty Images
Climb Inside a Crystal Cave
Explore a sparkly, hidden wonder in Spain.
By Tricia Culligan
From the December 2025 ⁄ January 2026 Issue
Featured Skill:
Knowledge Building,
Standards
Inside a Crystal Cave
Travel inside the Pulpí Geode!
What Is a Geode?
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Geodes are rocks filled with gems or crystals!
You may have seen a geode before. From the outside, it’s usually gray, lumpy, and not very interesting. It looks like a regular rock. But when you crack the rock open, surprise! It’s lined with crystals. Some crystals are clear. Others are colors like green or purple!
Most geodes are about the size of your hand. You can buy them at shops or see them in museums. The Pulpí Geode is one of the largest in the world. It’s big enough for people to walk inside!
A Crystal Palace
Experts say crystals started growing in the rocks about 2 million years ago. The crystals were hidden for many years.
Then, in 1999, a group of geologists was exploring a mine in Spain. Mines are underground areas where people dig to study rocks or find treasures like gold and silver. Imagine the scientists’ surprise when they found an unexpected treasure: a giant geode filled with massive crystals!
Today the geode is open for visitors from around the world. More than 100,000 people have been there so far. They gaze in wonder as the cave around them sparkles like diamonds. Some crystals are 7 feet tall. That’s taller than most grown-ups!
Would you like to climb inside this giant geode?
FACT FINDER
- WHAT is a geode?
- WHEN did scientists find the Pulpí Geode?
- HOW many people have visited the Pulpí Geode?
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