1. Corals are animals, not rocks or plants. Even though they look like colorful underwater trees or boulder formations, corals are made of thousands of tiny soft animals called polyps related to jellyfish!

2. The Great Barrier Reef is visible from outer space. Stretching over 1,400 miles along the coast of Australia, it is the largest living structure on the planet—so massive that astronauts can see it clearly from orbit.

3. Reefs are the underwater cities of the ocean. Coral reefs cover less than 1% of the ocean floor, but they are home to more than 25% of all marine life, including sea turtles, sharks, clownfish, and rays.

4. Coral polyps build their own stone skeletons. Hard corals absorb calcium from seawater and turn it into a hard limestone outer shell. When old polyps die, new ones grow right on top, slowly building up giant reef structures over thousands of years.

5. Corals get their vibrant colors from algae. Tiny plant-like organisms called zooxanthellae live inside the coral polyps. The algae get a safe place to live, and in return, they feed the coral energy made from sunlight and give them bright pink, green, and orange colors.

6. Reefs act as giant underwater shields. When huge storms or hurricanes hit the ocean, coral reefs break up powerful wave energy before it reaches the shore, protecting beaches and coastal towns from flooding.

7. Corals feed on floating microscopic food at night. When the sun goes down, coral polyps extend tiny, clear tentacles equipped with stinging cells to catch microscopic floating creatures (zooplankton) drifting by in the currents.