Until the late 19th century the vast majority of permanent settlements in Otago were on the eastern coast, which was rich in resources and has a more temperate climate. During this time inland Otago was largely used seasonally and for its mineral deposits, first by the Māori digging for pounamu stone, then European settlers searching for gold. With the advent of the railway, and refrigerated trade with Britain, inland Otago became more consistently productive. Rapid urbanisation has led to the creation of main population centers on the flatter eastern coast and in the high inland plains between the mountain ranges. This has been accompanied with immense social change in Otago's population, similar but distinct to the rest of New Zealand.