The Ürgüp Cones in the Cappadocia region of Turkey are structures left over from volcanic eruptions that were later converted into homes and churches.
The cones were formed after two great volcanoes, Hasan Dagi to the southwest and Erciyes Dagi to the southeast, erupted in a series of outbursts around eight million years ago.
The volcanic outpourings covered the surrounding landscape with horizontal layers of lava, ash, cinder and mud.
The lava cooled to form a hard, black basalt, while the ash coalesced into a soft, white rock, known as tufa.
After many thousands of years, the climate became cooler and wetter - more so than it is today. Heavy rainfall produced fast-flowing streams that drained north to the Kizil Irmak River or west to the great salt lake of Tuz Gölü.
These streams rapidly cut through the soft tufa and created a latticework of narrow gorges and steep-sided ridges. Further erosion widened the gorges and generated more intersections. The only parts of the ridges that remained were those protected by weather-resistant basalt boulders.
These were whittled away into isolated pinnacles, becoming the Ürgüp Cones. Their strong bands of color are due to mineral impurities, such as iron oxides, in the tufa.
Most of the cones, which rise abruptly from the valley floors to the west of Ürgüp, are clustered together, but a few stand by themselves. Each cone consists of a tall pillar of rock, often towering to 30m (100ft) and capped by a black, conical boulder known locally as a "fairy chimney". Horizontal bands of red, yellow or white stone define each cone.
Although the cones appear smooth and unbroken from a distance, innumerable doors and windows in the rock faces come into focus when they are seen close up.
The Inhabitants
The caves in the cones, and in the cliffs around them, have been inhabited almost continuously for more than 2,000 years.
The area was originally a center for agriculture.
During the Dark Ages, it became an outpost for Christian monks and hermits.
Monks at Ürgüp built small chapels and hermitages in the cones and cliffs.
Around Ürgüp, there are more than 150 rock-hewn churches. The most magnificent date from the 10th and 11th centuries. During that time, wealthy noblemen vied with each other to establish the best churches and monasteries. They often commissioned the Empire's most skilled artists to decorate the interiors with elaborate, strikingly colored frescoes.
In the 11th century, Moslems gained control of the region from the Christian Byzantine Empire. While local artists tried to maintain the tradition, they lacked the skill and flair of earlier painters. Following the Turkish invasions of the 13th century, all attempts to build and decorate churches ceased.
Today, many of the cones are still inhabited. They are very comfortable, with thick rock walls providing protection against extremes in temperature.