Somewhere in Seroe Colorado there are the secret Colony Caves of Aruba. These caves are the biggest in the whole Carribean, laying right underneath houses. The caves have a lot of stalagmites and stalactites. It is very hot and stuffy in there but very beautiful.
Aruba Explorers can take you to these caves for an amazing experience. You will have to subscribe to go so contact them, because they go in small groups only.