The Tünel was opened in January 17 1875 to provide an easy ride between the two neighborhoods of Pera and Galata, both in the new district of Istanbul on the hill north of the Golden Horn. Many people used to work in the low Galata, and live uphill in Pera. The Tünel, climbing about 60 meters, saved them this difficult walk.
Galata and Pera are now called Karaköy, and Beyoğlu, respectively. The lower station is named Karaköy, and the upper station Tünel Meydanı - Tünel Square (located on the lower end of Istiklal Avenue). A trip between the two stations now takes 1.5 minutes, with an extra two minutes of waiting between operations to allow passengers to board the train. The Tünel has two trains running simultaneously on the same track with two steel cars (with pneumatic tires) attached to each, and their cruising speed is roughly 25 km/h. There is a short duplex part of the track in the middle, where two trains pass side by side and continue their ways to opposite directions.
Today, the tiny Tünel is rarely useful for most of Istanbul's population, although it is still part of the municipal transport network and integrated tickets are valid. A larger (but separate) metro system is available, and other public transportation options include buses, cabs, and even a cable car (see article on Public transport in Istanbul).
When it opened, the Tünel was powered by horses. The line began being powered by electricity in 1910. The Tünel was nationalized in 1939 to become part of the new IETT (İstanbul Elektrik Tramvay ve Tünel) transportation organization. In 1971, the Tünel was renovated and modernized, and the original wooden cars were replaced by metal ones.