They say that beauty is in the eye of the beholder and never has that phrase been truer than in the face of these challenging architectural choices. From the gaudy to the downright weird, we take a look at some of the most questionable houses found around the globe.

But are these buildings unique or ugly? Click or scroll through, there's only one way to find out...

While it may look like a Tim Burton creation, this unusual property was part of an estate built by Thai artist Thawan Duchanee, that goes by many names including Baan Si Dum or 'Black House'.

It is part of a collection of 40 properties in Chiang Rai, Thailand, which Duchanee spent more than 30 years designing to create his own whimsical world. The estate is now home to the Baan Dam Museum.

Built in 1915 Haus Duldeck was designed by Rudolf Steiner as the home of the Grossheintz family. Love it or loathe it, the double cupola which emerges in the design of the building’s front and back gives it a rather foreboding look. 

Rudolf Steiner said about House Duldeck: "It is significant, that such a house could have been built once, because it stands there as a living protest against every traditional architectural style and construction type." Like the other buildings in proximity to the Goetheanum, the design is most definitely unusual.

Architect Ricardo Bofill was given the task of coming up with a model for this block of flats in Barcelona during the 70s. Inspired by the science-fiction novel Walden Two by behavioural psychologist B.F. Skinner, this labyrinth-like structure is supposed to function as a 'vertical city'.

Originally covered in tiles, these began to fall off and became quite a hazard. They were mostly removed in the 90s and the strange putty-coloured building was painted instead.

We're not sure too sure how we'd feel about having huge boulders as neighbours, like this cottage in Plougrescant, France.

Built in 1861 in a precarious position at the tip of the peninsula, at the time construction was much less regulated. To protect it from the frequently violent coastal weather, the house was flanked on either side by two giant rocks, hence it's local nickname.

Residents of Berlin, Germany, will no doubt recognise this rather odd looking apartment building. Known as Kreuzberg Tower and Wings, the structure was designed by American architect John Hejduk and was completed in 1988, shortly before the Berlin Wall fell in 1989.

Many have spotted that its two identical side wings look like simplified faces – we also think they bear a resemblance to owls!

Ugly home hunter, Hannes Coudenys, started the blog Ugly Belgian Houses to document the architectural oddities that seem to flourish in his home nation. Just like this 'pyramid' house, he's captured some incredibly challenging designs for a coffee table book.

This is just the tip of the iceberg...

Another home courtesy of Ugly Belgian Houses. Although the front of this house looks pretty normal, the strange scale design on its side really makes it earn a spot on this list.

We can’t help but wonder what the architect was thinking when they came up with this ugly addition to an otherwise normal-looking property.

Brutalist architecture has always divided opinion. Habitat 67, a remarkable housing estate in Montreal, was designed by architect Moshie Safdie as part of his McGill University thesis.

The dedicated architectural landmark, which was highly celebrated locally, has grey-beige modules stacked on top of one another to form 148 residences. We have to say, this one has rather grown on us.

It may look like a boulder, but this is actually someone's house. Sandwiched between two enormous rocks, Stone House is constructed from mortared masonry in order to seamlessly blend into its surroundings.

Located in the mountains of Fafe, Portugal, it was inspired by the Flintstones and has even appeared in a Portuguese film called Moon. 

This quirky property is home to American multimedia artist Ricky Boscarino, who also designed the home. Luna Parc is located within the 8.5-acre (3.4ha) wooded landscape of Sandyston, New Jersey, and was inspired by the Hundertwasser House in Vienna, Austria, and Gaudi’s Park Guell in Barcelona, Spain.

The main 5,000-square-foot (465sqm) building houses thousands of absurd and exotic artefacts for visitors to explore. The unique home comprises of a semi-private home, museum and workshop.

During his stint as Mayor of Suwon City in South Korea, Sim Jae-deok campaigned to improve local toilets. He became so obsessed with his crusade that he demolished the house he'd lived in for 30 years, and replaced it with this toilet-shaped property.

Designed by architect Go Giung, the home was finished in 2007. Following Jae-deok’s death in 2009, his family donated the property to the city, turning it into a toilet-themed museum.

Built back in 1985 in Austria’s capital city, Vienna, Hundertwasser house has become quite the tourist attraction. The expressionist-style colourfully decorated apartment building was designed by Friedensreich Hundertwasser and Joseph Krawina, also inspired by Gaudi, and has quickly become one of Vienna’s most visited buildings.

Surprisingly, Hundertwasser residents can decorate around their windows however they choose. 

What could be more normal than homes shaped like flying saucers? Known as the Sanzhi UFO Houses, these pastel pods were abandoned for years. Located in New Taipei, Taiwan, the futuristic properties were never completed.

Some say this was due to the site being an ancient burial ground, while others attributed delays to financial loses. Either way, and perhaps for the best, the UFOs were demolished in 2010.

If you like your solitude, this house is guaranteed to keep the neighbours away. With its barred circular windows and red brick merlons on the roof, the home closely resembles a prison fortress, uninviting and pretty scary.

You may remember this end-of-terrace property from when it went viral in 2016. The so-called 'Hitler House' looks curiously like the German dictator thanks to its slanted roof and prominent door lintel, both of which have an uncanny resemblance to Hitler's iconic side-parting and moustache.

Located in Swansea, Wales, the property hit the headlines when it reportedly went on the rental market for just £85 ($108) per calendar month.

Located in Poplar, East London, The Balfron Tower was designed by Hungarian architect Erno Goldfinger in 1963. The tower block is a prime example of New Brutalist architecture, which swept Europe between the early 50s and mid-70s.

Drab and unforgiving to some eyes, the tower covers 27 storeys and is now Grade II listed.

Another questionable Belgian home. The jagged bright blue windows and oddly pointed roof resemble something straight out of a fairytale, but not in a good way.

The layered roof of the garage alongside the main house is really the icing on the cake. 

Another shocker discovered by the blogger behind Ugly Belgian Houses, this minimalist building has a curious resemblance to a modern-day emoji, which probably isn't the look the architect was aiming for...

A further home that was captured by Ugly Belgian Houses is this unique property. A fusion between a garage and a rooftop apartment, it doesn't quite have the symmetry or glamour of a penthouse suite. 

This flying saucer-inspired property was designed by Finnish architect, Matti Suuronen. Known as the Futuro House, this prefabricated building is one of only 100 built in the world. The pod is built from fibreglass-reinforced polyester plastic and measures just 13 feet (4m) in height and 26 feet (8m) in width. 

This model was most recently displayed at Exhibition Centre WeeGee in Finland, and, despite being an acquired taste, has garnered fans from all over the globe. 

Unsurprisingly, this unique property in Dalat, Vietnam, is also known as the Crazy House. Designed by architect Dang Viet Nga, the building is actually a guesthouse, drawn from Viet Nga’s vivid imagination. 

The structure looks as though it’s dripping in oozing black goo. However, once inside, the hotel offers guests a wide range of whimsical, animal-inspired accommodation, with options like the ‘bear room’ and the ‘tiger room.’

Located on Highway 395 in America, the Lemon House Inn is an iconic roadside attraction on the edge of the Eastern Sierra Nevada Mountains.

With one bedroom, the submarine-style property also features a unique garden, decorated with dinosaur skeletons and faux cacti.

This lopsided property seems to be a failed attempt at modernist architecture. The roof looks like it is sliding out of place – does anyone else feel seasick?

Developers across Europe are always striving for innovative designs for large-scale housing projects. This particular scheme, located in Rotterdam, was designed by Piet Blom in 2013.

Blom’s concept was to create a village in which every house represented a tree, uniting together to become a forest. We don’t know about you, but we think Blom perhaps couldn't see the wood for the trees...

This angular, bulky and off-balance home looks almost like an optical illusion, with the main body of the building appearing to sink into the ground.

It leaves us wondering what the architect was thinking...

We return to Belgium for another delight found by Ugly Belgian Houses. This obscure home may look a bit like a cat's face, but it certainly isn't as cute...

This home in Ostend is reminiscent of flat-pack furniture gone wrong. This bonkers property may look like one of Picasso's impressionist paintings, but it certainly doesn't carry the critical acclaim!  

Known as Grandma Prisbrey's Bottle Village, this unique home is built from numerous recycled and landfill objects, including doll heads and thousands of empty glass bottles.

Located in Simi Valley, California, the village was the brainchild of Tressa "Grandma" Prisbrey, who spent more than 20 years building her dream home. It may not be to everyone's taste but lots of people love this quirky build. The village has been labelled a historical landmark by the State of California and is listed on the National Register of Historic Places.

This former council house is located in Kingston upon Hull, East Yorkshire. Local graffiti artists have taken the facade into their own hands, creating a unique canvas.

The Bankside Gallery project was a way for Hull City Council to improve the visual draw of unsightly properties across the city. We'd love to see the before photos...

Captured by a Flickr user in a Vancouver neighbourhood, this huge brown residence certainly bears a confident footprint. It is positively hulking out compared with the other homes on the street.

Also, the random window shapes are making us a little anxious...

The Haines Shoe House is somewhat of a roadside marvel in York, Pennsylvania, with visitors travelling from around the world to step inside this architectural phenomenon.

Completed in 1949, the house covers five storeys. You can even visit the property's tea room, located in the shoe's heel.

Known as ‘poppy palaces,’ due to their links to the opium trade, these opulent candy-coloured residences began popping up around Kabul’s equivalent of Beverly Hills, designed for the area’s most wealthy residents.

The garish homes feature elements of "narco-tecture", including outdoor chandeliers, indoor pools, rooftop fountains, and basement Asiatic-inspired nightclubs, all for the shocking price of reportedly around £9,500 ($12,000) a month.

These prefabricated Japanese dome-homes may well be modern engineering marvels, designed using polystyrene for its durability and energy-saving properties.

But, we can’t help but think they look a bit like pimples…

Love them or hate them? These funky little igloo houses can be found on the gorgeous landscape of Denmark’s Faroe Islands.

Placed on concrete foundations and constructed of asphalt panels, these prefabricated tiny homes are designed to withstand anything Mother Nature can dish up, but as the panels can sprout both grass and moss, they have a tendency to look a bit scrofulous!

Known as the Snail House in Sofia, Bulgaria, this funky property definitely resembles a technicolour version of its namesake.

Five storeys tall and strategically engineered such that all of its appliances appear to be part of its decor, the residential building was designed by architect Simeon Simeonov, who ensured that the structure has no straight walls or corners to enhance its resemblance to, well, a slug.

And speaking of slugs, this earthship in New Mexico, USA definitely looks like something that might turn up in your garden.

However, the alien-looking exterior eco house was in fact built to withstand natural disasters or apocalypse-type events, and is part of a larger community of similar structures, each with its own food-producing greenhouse, and enclosed by a wall of tyres.

Loved this? Now discover more of the world's most unusual homes