The peaks of three volcanoes – Erciyes, Hasan and Melendiz Dağları – dominate Cappadocia. It was their eruptions, which covered the former plateau of Ürgüp in ash and mud some thirty million years ago, that provided the region’s raw material: tuff, formed by compressed volcanic ash. Erosion has worked on this soft stone ever since, to form the valleys and curious fairy chimney rock formations for which the region is so famous.
The original eruptions created a vast erosion basin, dipping slightly towards the Kızılırmak River, which marks an abrupt division between the fantasy landscapes of rocky Cappadocia and the green farmland around Kayseri. Where the tuff is mixed with rock, usually basalt, the erosion process can result in the famous cone-shape chimneys: the tuff surrounding the basalt is worn away, until it stands at the top of a large cone. Eventually the underpart is eaten away to such an extent that it can no longer hold its capital: the whole thing collapses and the process starts again.
In the Cemil valley, near Mustafapaşa, the cones give way to tabular formations – table mountains – caused by the deep grooves made by rivers in the harder geological layers. Another important region lies northwest of the Melendiz mountain range – the valley of the Melendiz Suyu, or Ihlara valley. The most individual feature of this region is the red canyon through which the river flows, probably the most beautiful of all the Cappadocian landscapes.