Pakistan turns a year older today and to commemorate the big day, Google is gifting us a doodle!

Illustrated in the Doodle artwork is the fortified eastern entrance of Pakistan’s historic Khojak Tunnel, one of the nation’s oldest and longest underpasses.

Construction on this iconic landmark began in 1888 to extend the area’s railway through the Khojak pass of the Toba Kakar mountain range, which was at the time impossible to cross by train.

The Khojak Tunnel’s construction was an unprecedented undertaking in the South Asian subcontinent. Over 19 million bricks were required, most of which were kilned at the rugged site, and builders burned more than 6,000 candles to illuminate their work in the dark space. Upon its completion in 1891, the 3.9-kilometer Khojak Tunnel became the fourth-longest underpass in the world.

To honour this feat of civil engineering, in 1976 the Pakistani government printed a depiction of the Khojak Tunnel on its five-rupee note, which remained in circulation until 2005.

This isn’t the first time Google has celebrated Pakistan’s birthday with a drawing. In the past, the search engine has also paid homage to Pakistani icons such as Noor Jehan, Abdul Sattar Edhi, Waheed Murad, Saadat Manto and Nusrat Fateh Ali Khan to name a few.