Bidar is a hill top city in the north-eastern part of Karnataka state in south India. It is the headquarters of the Bidar which borders Maharashtra and Telangana. The city is well known for its many sites of architectural, historical and religious. Bidar is home for the second biggest Indian Air Force training center in the country. The IAF Station Bidar is used for advanced jet training of prospective fighter pilots on BAe Hawk aircraft. Bidar city is known for its Bidri handicraft products, and its rich history. Bidar is also considered one of the holiest places for Sikh pilgrimage. Unlike other places in the region, Bidar is the coldest and wettest place in north Karnataka. Ancient Karez System in the city have been recently discovered. The Karez (Qanat) is an underground network of aqueducts for water supply. The Bidar Karez, built in the 15th century, is more than 3 km (1.9 mi) long with 21 air vents. Underground canals, built to connect underground water streams, were meant to provide drinking water to civilian settlements and the garrison inside the Bidar fort.