Gozo is considerably smaller than the main island of Malta, covering an area of only 64 sq km. Most of the towns and villages are to be found on the tops of hills, the highest of which only reach about 200 m.
There are numerous caves on the island, all of which are formed in limestone. As with Malta this is a very arid island, and with rivers which only run intermittently. However, there are numerous wieds, which have been formed by thewinter flash floods. Because the limestone is horizontally bedded, this has influenced the way in which the caves have been formed and, in fact, the caves of Gozo are known for their concretions, which far surpass those in the caves on the main island.