Most houses are built around a very idea: they have to be comfortable and safe, their main function being to provide shelter to its inhabitants. But for some people, the old “four walls and a roof over your head” thing seemed a bit too boring. With this in mind, we’ve put together a list of some of the most unusual places someone has ever called home:

20. Nautilus House

Designed by Mexican architect Javier Senosiain and located on the outskirts of Mexico City, the Nautilus House is a great example of Bio-Architecture – the creation of buildings inspired by natural, organic forms.

19. Pickel Barrel House

Located in Grand Marais, Michigan, this cartoonish house is made from two barrels: the taller one has two stories, with the ground level being the living area and upstairs is a bedroom. The smaller barrel, on the other hand, is a kitchen.

18. Windsor Crooked House

Originally constructed in 1592, the Crooked House of Windsor got its slant in 1718, when it was rebuilt using unseasoned green wood. Nowadays employed as a tea house, this miniature Tower of Pisa located in the heart of London also has a secret passageway to Windsor Castle.

17. Tardigrade House

Built by architect Sam Tsui in Berkeley, California, the Tsui House is touted by its creator as one of the safest homes in the world, while also energy sufficient and environmentally friendly. It’s also called the Tardigrade House, inspired by a famously sturdy little creature that’s been known to survive trips to Outer Space and back.

16. Haines Shoe House

Originally built by a shoe salesman as a form of advertisement in 1948, the Haines Shoe House in Bellam, Pennsylvania is no ordinary commercial – and entirely worthy of its place on this list. The initial owner reportedly showed an architect a boot and told him “build me a house like this”.

15. The Desert House

Located in the middle of the desert, in Joshua Tree National Park, California, this unique house blends in perfectly with its surroundings thanks to its unique design. From afar if seems to resemble a sort of rock formation, or a huge shelled creature if you have enough imagination.

14. Boeing 727 Home

The Boeing 727 airliner is quite popular as both a passenger aircraft and a private jet – but what about actually living in one? One man in Oregon has actually bought a decommissioned Boeing 727-200 and converted it into a home.

13. Mushroom House

Located in a wooded area around the town of Perinton, New York, this house is comprised of four 80-ton pods resting on reinforced concrete stems 14 to 20 feet high. This, together with its surroundings, gives the complex its mushroom-like appearance.

12. Klein Bottle House

To the layperson, this might look like just a really bizarrely-shaped construction, but the Klein Bottle House is the kind of building architects drool over. A Klein bottle is basically what you get when you put two Moebius strips together, the sort of anomaly mathematicians enjoy – and is the sort of arcane notion the designers of this house located southeast Melbourne, Australia played with when creating it.

11. Bubble Castle

Created by designer Antti Lovag, the Bubble House complex located on the southwestern coast of France were built without the use of any sharp angles or straight lines, in an attempt to blend is as smoothly as possible with its surroundings. There are even palm trees and waterfalls inside, making it even more in tune with nature.

10. Stone House

From the outside, this house looks like a really big rock with a roof placed on top and some windows carved into it. But it’s actually a real home, with all the amenities you’d expect for it to be livable, as well a fireplace and a swimming pool on top of that.

9. Cube Houses

The cube house complexes in the Dutch cities of Rotterdam and Helmod are all about form as well as function. Each home is a cube tilted at 45 degrees, built upon a hexagonal pylon. This resembles the trees in a forest, with the canopy above the tree trunk, ensuring most of the living space is above ground level.

8. Dick Clark’s Flintstones Inspired Home

Dick Clark was known as “the world’s oldest teenager”, so it’s perhaps no surprise he actually owned a house that resembles the one Fred Flintstone, from the extremely popular 1960s cartoon sitcom, lived in. It’s a comfortable, two bathroom home, which, apart from the novelty of the Stone Age-theme, also offers breathtaking views of the Pacific Ocean.

7. Toilet House

This toilet-shaped house in Suwon, South Korea might seem like a joke, but it’s actually making a very important point. Built by former Suwon mayor Sim Jae-Duck, it is now part of a toilet theme park which aims to raise awareness around the issue of hygiene, with over 2 billion people in the world lacking access to proper restrooms.

6. Gold Pyramid

If living in a pyramid wasn’t already awesome enough, how about one plated with 24-carat gold? Built by Jim and Linda Onan in Wadsworth, Illinois, this six-story-tall, 17,000-square-foot house is surrounded by a moat and a series of Ancient Egypt-themed features, like a 50-foot statue of a Pharaoh.

5. Mother Goose House

The rather unremarkable town of Hazard, Kentucky can nevertheless boast one of the most interesting homes in America: the Mother Goose House. Built basically on a whim in the second half of the 1930s, the house features a goose head on its roof, but also has three bedrooms, a living room, a kitchen, a bath, dining room, and large family room underneath.

4. Sliding House

From the outside, this house in Suffolk looks like any other normal home. But flip a switch and this inconspicuous shell literally slides away, revealing the actual structure with its glass walls. It’s a neat idea, especially useful during a beautiful summer day.

3. Heliotrope

Built by German architect Rolf Disch in his native Freiburg, this intriguing house is the first ever built to actually produce more energy than it needs. The house features a whole range of systems making it as efficient and environmentally-friendly as possible, even rotating to get as much solar energy as possible.

2. Steel House

Designed and built by the late sculptor Robert Bruno, this peculiar steel structure is both a home and a work of art. It took its creator 23 years to build this house, which resembles some sort of strange creature overlooking the wilderness, using 110 tons of steel.

1. Winchester Mystery House

This amazing mansion was built by Sarah Winchester, heiress to the Winchester rifle fortune, who was afraid she was haunted by the souls of those killed by the popular firearm. The only solution was to continuously build a maze-like house with features like long hallways, secret passages, dead ends, or doors opening into walls. Construction went on without interruption from 1884 to 1922, when Sarah Winchester died.