The vast majority of buildings people interact with on a daily basis are fairly ordinary. Brick or stone houses. Mirrored glass office buildings. Wooden sheds. They do a job and do it well and we don’t expect much more from them. But sometimes architects lose their minds and design something so weird that it’s amazing they could find contractors to build the thing. These are five of the most baffling buildings ever constructed.

The Atomium

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The Atomium in Brussels was built to be surreally weird, to which we say, well done, Brussels. It was originally built for the 1958 World’s Fair. The peculiar shape is meant to resemble an iron crystal, though blown up to 165 billion times its original size. Visitors walk through a series of tubes and bulbs, are treated to an extensive exhibit about the history of the building and see a striking 360-degree panorama of Brussels. If you’d like, you can make that panorama the backdrop for a meal of entirely Belgian origins at the restaurant at the top of the crystal.

Ryugyong Hotel

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North Korea’s a baffling place, which means the prize jewel of its spartan capital, Pyongyang, has to make the list. We’re talking about the huge pyramid that is the Ryugyong Hotel. Everything about the place is a drab grey except for the massive glass, steel and concrete spike in the middle of the city. Ostensibly, it’s a hotel, but by all reports, the building is literally a shell. Nothing’s inside, no one visits, there aren’t any active tenants and the most revealing look people have had of the building is the few pictures of the outside that managed to make their way into circulation. For 32 years, the building has towered over Pyongyang without ever officially opening its doors or even having electricity installed.

Habitat 67

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Habitat 67 in Montreal looks like the kind of thing we built with those big wooden blocks we all had when we were kids. Big rectangles lay on top of each other in what looks like a completely random order and with no consideration for anything you might want to put on the inside. In reality, that’s kind of what happened. The structure is made of 354 different modules stacked on top of each other. It’s primarily used as living spaces and would certainly be an interesting place to come home to.

Casa do Penedo

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Most of the time, people make their homes out of a bunch of stones stacked on top of each other. That, and you’d generally clear the construction site of large obstructions before you build something. The Casa do Penedo (which roughly translates to “House of Stone” in English) in Moreira do Rei, Portugal, doesn’t follow either of those rules. Instead, it looks like someone took a regular house, melted it down, and poured it into the crack between two huge boulders. Understandably, The Flintstones is cited as a major inspiration for the house.

There was actually a long internet fight about whether or not the Casa do Penedo was even real, with plenty of internet experts crying foul from their computers. To be fair, at the time of the argument, the house had only ever been photographed from two angles and most of the pictures had been edited in some way. Eventually a television special and Daily Mail article were written about the house, proving its existence. But for a little while, it looked like the Casa do Penedo was someone’s Photoshop training exercise, not a legitimate construction project.

The Eden Project

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England isn’t particularly known for its natural biodiversity or wilderness. It’s a pretty country to look at, but you’re not going to find the kind of flora and fauna there that you would in more tropical places. Unless you were going to the Eden Project in Cornwall, which is a series of environmental biomes used mostly for education. There are domes for the rainforest, California, South Africa, the Mediterranean and a huge garden for utility plants. In a few short hours, visitors can travel the warmer climates of the world and be home for Yorkshire pudding before the sun goes down.