The Great Trans-Siberian Railroad
Easily the longest railroad in the world, the Trans-Siberian Railroad spans the distance from Moscow to Vladivostok - nearly the whole of the width of Russia. This great railway and its branches have served since the late 19th century to connect the halves of Russia, as well as allowing for transport to locations like Mongolia and China. It has played a major role in Russian history since its construction, influencing the course of wars, trade, and cultural development. It's also served as the backdrop for movies and literature, including the Woody Harrelson movie Transsiberian.
At around 5,750 miles, the Trans-Siberian is the longest railway in existence. Taking the trip from end to end lets one go through seven timezones and takes a full eight days to complete. Most of the journey is through Siberia, hence the name, but in truth the railway covers all but the very westernmost portion of Russia. There is no single train along this route, but rather a number of different trains that stop in different locations along the way, carrying passengers or cargo. In addition, the railway has several branches, such as the Trans-Manchurian and Trans-Mongolian, that begin in the same place but then swerve south to connect Russia to Asia. The network overall is deeply complicated and intricate, as of course many trains use the long track for some portion of their route before heading elsewhere. The true Trans-Siberian is considered to be the route from Moscow to Vladivostok.
Construction on the railway began in 1891, and was blessed by Tsar Nicholas II in Vladivostok. The construction met with many challenges early on, one of the main ones being the presence of the massive Lake Baikal in the path of the railway. At first ferries (and sleighs, in the winter) were used to get passengers from one side to the other, because building a railway around the edge of the lake was too great a delay. Finally a southern spur was built, but for a long time a ride on the Trans-Siberian also ensured a boat trip.
The building of the railroad represented a massive change in how trading and exporting could work, with Siberian grain that was previously difficult to access now being a viable source of food or trade goods. In addition, goods could be transported from Japan to Europe without the need for sea travel. This function has become especially vital of late, as international piracy during sea transit is an increasing concern - the Trans-Siberian both shortens travel time and reduces the risks involved. The Trans-Siberian has also influenced wars (the Russo-Japanese war was in part lost because of the lack of a second track for the Trans-Siberian) and culture (allowing freer movements of populations).
Of course, pop culture has also been influenced, with works using the Trans-Siberian as a background for their stories. One of the more famous is the thriller Transsiberian, starring Woody Harrelson. Interestingly, the movie is actually set on the Trans-Manchurian branch for the most part, as the characters start in Beijing. It follows a tale of drug smuggling, murder, and betrayal, with Emily Mortimer trying to reject the advances of a possible drug trader and hiding the goings-on from her husband. All of it is set against the backdrop of Russia as the four main characters travel through it. What could be a more dramatic setting than this - the grandest railway in the world?