Check Out These Photos from the Construction of the World’s Longest Train Tunnel

Building 35 miles of tunnel beneath the Swiss Alps isn't easy, but it sure looks cool.

Gotthard Base Tunnel
AP Photo/Keystone/Karl Mathis

Earlier today, European leaders officially opened the Gotthard Base Tunnel, the longest rail tunnel in the world—a 35-mile link through the heart of the Swiss Alps that, at full capacity, will carry around 325 trains per day across the massive mountain range. But as impressive as the tunnel's capabilities are, they pale in comparison to the two decades of work it took to plan and dig the massive piece of infrastructure.

Enough rock was pulled from beneath the Alps to build five Great Pyramids, culled by tunnel-boring machines longer than drag strips. Teams encountered 73 different types of rock, much of which was ground up and integrated into the 140 million cubic feet of concrete used to make the tunnel. And working conditions were hazardous, to say the least; far beneath the surface, temperatures climbed as high as 115º Fahrenheit, and nine workers died in accidents during construction.

So in honor of the incredible work that went into building this transformation link through Europe, we put together a gallery of images documenting the years of blood, sweat, and tears that went into building the Gotthard Base Tunnel. Check 'em out...and feel free to click the link in the previous sentence for some musical accompaniment.

All photo captions are via AP/Getty.

MICHELE LIMINA/AFP/Getty Images

A controlled blast 23 June 2006 removes a rock formation called Nollen over Gurtnellen that threatened to fall, endangering traffic on the Gotthard route connecting Switzerland to Italy. Authorities decided to blast the cliff face after two German citizen died from a falling rocks 31 May 2006.

Johannes Simon/Getty Images

Caterpillars are operate inside the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. The completion is planned for 2018.

Johannes Simon/Getty Images

A giant drill removes Alpine rocks at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. The completion is planned for 2018.

Johannes Simon/Getty Images

Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. The completion is planned for 2018.

Pier Marco Tacca/Getty Images

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016.

Pier Marco Tacca/Getty Images

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016.

AP Photo/Keystone/Arno Balzarini

The tunnel drilling machine "Sissi" breaks through the last section of the Gotthard Base Tunnel near Sedrun in the canton of Grisons, Switzerland, Oct. 15, 2010. With 57 kilometers (35-miles) the new St. Gotthard tunnel is the world's longest tunnel. The 13.157 billion Swiss francs (9.6 billion euro, 13.6 billion US dollars) Alptransit project, which is due to be operational in 2016, constitutes the center piece of the New Railway Link through the Alps.

Pier Marco Tacca/Getty Images

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016.

Samy Golay/TiPress/Getty Images

Workers celebrate the break trough of the second shaft of Gotthard Tunnel on October 15, 2010 in Sedrun, Switzerland. The world's longest tunnel, which has been under construction for 14 years, is not expected to open for service until at least the end of 2016.

AP Photo/Keystone, Gaetan Bally

The entrance to the "Erstfeld" north portal of the Gotthard Base Tunnel (background) and a conveyor belt for the excavated material (front), near Erstfeld in the canton of Uri, Switzerland. The company in charge of the project says there are only 59 feet (18 meters) left to dig before completing the last section of the new Gotthard Base Tunnel. When it is opened for traffic in 2017, the Gotthard Base Tunnel will supplant Japan's 33.5-mile (53.6-kilometer) Seikan Tunnel as the world's longest—excluding aqueducts—and allow millions more tons of goods to be transported quickly through the Alps by rail.

Philipp Schmidli/Bloomberg via Getty Images

Workers walk alongside a support freight train inside the east section of the Gotthard Base Tunnel in Faido, Switzerland, on Tuesday, July 15, 2014. Drilling and blasting on the 57-kilometer (35-mile) railroad tunnel linking Erstfeld in German-speaking central Switzerland and Bodio in the Italian-speaking south began in 1996, with completion expected in 2017.

FABRICE COFFRINI/AFP/Getty Images

A train makes its way at the north entrance of the new Gotthard Base Tunnel the world's longest train tunnel on the eve of its opening ceremony on May 31, 2016 in Erstfeld. The new Gotthard Base Tunnel (GBT) is set to become the world's longest railway tunnel when it opens on June 1.The 57-kilometre (35.4-mile) tunnel, which runs under the Alps, was first conceived in sketch-form in 1947 but construction began 17 years ago.

RUBEN SPRICH/AFP/Getty Images

Swiss President Johann Schneider-Ammann (C) cuts the ribbon next to Swiss Federal Railways (SBB) CEO Andreas Meyer and Swiss Transport Minister Doris Leuthard (R) during the opening ceremony of the Gotthard Base Tunnel, in Pollegio, Switzerland, on June 1, 2016. The world's longest tunnel officially opened on June 1, with the trailblazing rail passage under the Swiss Alps aiming to ease transit through the heart of Europe.