When Darwin sailed round the world on the ‘Beagle’ in the 1830s he noticed small islands made of low circular coral reefs like those in the photo. These circular reefs were scattered across the deep oceans of the tropics. Try ‘thinking like Darwin did’ to work out how they formed. Use the search engine from our website to find the activity.
This is one of many ELIs in our 'Investigating the Earth' category.