A quarry is used to cut stone from the ground. A quarry needs to be placed in a large flat area. Once built, stonecutters will work in the quarry, digging it deeper and deeper while producing stone.
Quarries take more work to produce stone than collecting it from the landscape. However it is the only way to produce stone - other than through trading - after the loose stone on the ground has been collected.
Quarries have a limited amount of material that can be removed from them. Once it is gone, the quarry will no longer be useable.
Quarries cannot be removed. After the quarry is no longer useful, the building can be taken down, but the hole that has been dug in the quarry won't ever be available for any other use.
Quarries are dangerous - the chance of workers dying in an accident is higher than any other profession. Educated citizens have a reduced chance of dying in a quarry.