Scottland has no famous karst areas, as a matter of fact Scotland is the last remains of an ancient orogeny which mostly crystalline rocks. Despite being geologically very interesting, this area is built of crystalline, metamorphic and insoluble sedimentary rocks like old red, a famous red sandstone. Scotland has small patches of marble karst, some tectonic caves and numerous small sea caves along the coast.
The most interesting karst area in Scotland is Assynt, a small belt of marble, metamorphic limestone, which contains numerous narrow but rather long river caves. This belt runs north from Ullapool to the northern coast. Here, at the coast, Smoo Cave is located, a combination of karst cave and sea cave, and Scotland's only show cave.
Other small caves are interesting primarily because of their historic background, like St Ninian's Cave and King's Cave.
Scotland is the remains of old mountains, and this geologic history produced several valuable ores. Mines of Scotland produced iron and coal. Some of them are open to the public now.