JIM MCMAHON/MAPMAN®

A church in Barcelona, Spain, has been under construction for 144 years—and it’s still not finished! This past February, with the addition of a massive cross atop the cathedral, Sagrada Familia reached its final height of 172.5 meters (566 feet). At roughly 57 stories, it’s the tallest church in the world.

Construction of Sagrada Familia began in 1882. When its architect, Antoni Gaudí, died in 1926, only 15 percent of the church was complete. Ten years later, his plans were damaged during a civil war. Modern technology like computer simulations and 3-D printed models have made it easier to finish the complex structure. With each passing year, Gaudí’s vision is closer to becoming a reality.