In the present-day Republic of Turkey, an underground rail line made its official debut in Constantinople (now Istanbul). At the time, Constantinople was the capital of the Ottoman Empire. The Tünel (the Turkish word for “tunnel”) is located at the northern shore of the Bosphorus strait’s primary inlet popularly known as the Golden Horn. The Tünel is second only to the London Underground (opened in 1863) as the oldest surviving subterranean urban rail line in the world. Consequently, the Tünel is the oldest extant subterranean urban rail line in continental Europe; an older underground railway line in Lyon, France, that had been opened in 1862 now serves as a road tunnel instead.
The origins of the Tünel can be traced to 1867 when French engineer Eugène-Henri Gavand was vacationing in Constantinople. During his visit to the Turkish city, Gavan was dismayed by the unusually large number of people – a daily average of 40,000 – struggling to travel on a steep main street called Yüksek Kaldırım Avenue between the major neighborhoods of Pera (now Beyoğlu) and Galata (now Karaköy). Gavand came up with the idea of an underground railway to facilitate travel on that challenging route.
After returning to France, Gavand drew up plans for this transportation project. The following year, he returned to Constantinople to present these plans to the Ottoman Empire’s central government known as the Sublime Port. Gavand’s proposal for a subterranean line was approved, and in 1869 Sultan Abdülaziz of the Ottoman Empire granted the French engineer with a concession to undertake the project.
Garvand’s efforts to set up a company in France to build the rail line were halted due to the Franco-Prussian War. Garvand subsequently made his way to England, where he was able to establish the Metropolitan Railway of Constantinople for building the subterranean line. Construction on the Tünel began during the summer of 1871 and it was completed towards the end of 1874.
The Tünel remains a part of the region’s municipal transportation network, with bookend stations at Beyoğlu and Karaköy. The line is operated by the Istanbul Metro, a public enterprise that is part of the Istanbul Metropolitan Municipality.
For more information on the Tünel, please check out https://en.wikipedia.org/wiki/T%C3%BCnel.