Cappadocia, a semi-arid region in central Turkey, is known for its distinctive “fairy chimneys,” tall, cone-shaped rock formations clustered in Monks Valley, Göreme and elsewhere. Other notables sites include Bronze Age homes carved into valley walls by troglodytes (cave dwellers) and later used as refuges by early Christians. The 100m-deep Ihlara Canyon houses numerous rock-face churches. Some caves are now hotels in towns such as Ürgüp and Ortahisar. Other historical attractions include the Göreme Open Air Museum, a monastic center with stone-cut Byzantine churches ornamented with frescoes, and the multileveled Derinkuyu and Kaymakli underground cities. The craggy Üçhisar Castle, atop the highest land formation in the region, offers views from the summit, while hot-air balloons (operated by several local companies) survey the area from the sky. Rugged, multicolored canyons such as Rose Valley are favored for hiking. A major wine producer, Cappadocia is also home to many vineyards.