Limestone is a rock made from carbonate. It was formed by coral in shallow seas.

You can tell that you are in limestone country, because there are lots of caves. These have been hollowed out by the action of water that has reacted with [?] in the atmosphere to make very slightly rain. The water trickles through the rock, slowly dissolving it.

Limestone is extracted in .

Uses for limestone include making (calcium oxide), lime (calcium hydroxide), cement, and roadstone.