Well, this is technically not a location as you know, it moves! But then this also happens to be one of the most popular locations that we could think of given the monster hit that Chaiyya Chaiyya was. But the fact is that this train has been used in many Tamil movies before, as early as a decade and a half before UyirE/ Dil Se came along. The earliest we could think of was the 1982 released super hit movie ‘Moondraam Pirai’ in which the train was used in the climax scene. In these days when directors fly to foreign locales at the drop of a hat, the fact that this train was used in a movie that was released in 2009 (Kaadhalil VizhundhEn), says a lot about this uniquely cute ‘location’.

About the location (from Wiki):
The Nilgiri Mountain Railway (NMR) connects the town of Mettupalayam with the hill station of Udagamandalam (Ootacamund or Ooty), in the Nilgiri Hills of southern India. Both towns are in the state of Tamil Nadu. It is the only rack railway in India and uses the Abt system.

The Nilgiri Mountain Railway is one of the oldest mountain railways in India. Under consideration since 1845, the line was finally opened by the British in 1908, and was initially operated by the Madras Railway Company. The railway is one of the few in the world that is dependent on steam locomotives. In July 2005, UNESCO added the Nilgiri Mountain Railway as an extension to the World Heritage Site of Darjeeling Himalayan Railway, the site then became known as “Mountain Railways of India.” after it satisfied the necessary criteria, thus forcing abandonment of the modernisation plans.

Movies shot at this location:
Chaiyya Chaiyya from Uyire/ Dil Se
Climax scene from Moondraam Pirai
Oru Kaadhal Devathai from Idhaya Thaamarai
Unakkena Naan from Kaadhalil VizhundhEn
Raathiri Neram Rayiladi Oram from Brahma