Living beneath the waves has long captured the imagination of dreamers, designers and explorers, inspired by tales like Atlantis. Today, with rising sea levels and a growing curiosity about what lies in the ocean's depths, underwater structures are moving from fantasy to reality.
Click or scroll on to explore the world’s most incredible underwater properties, both real and conceptual...
With the current climate crisis causing rising sea levels, more architects than ever before are turning their hands to designing new habitats for living on the water. But unlike most, this design from ATDesignoffice ventures beneath the waves as well as surfing on top of them.
If the project is realised, the city would cover 10.8 million square feet (1 million sqm) of ocean and would be made up of four miles (6.4km) of hexagonal and triangular modules, which would be linked by underwater tunnels and navigated by electric cars.
On the surface, buildings, pastures and gardens would be connected by a series of canals, so – as in Venice – inhabitants would mostly get around by boat or even submersible vehicles.
If built, the incredible floating city would no doubt become a tourist destination, so designs include a cruise port terminal for large ships, plus a marina for small yachts and a dock for civilian submarines.
Most of the residences, luxury hotels and public spaces will be largely above the waves, such as the huge floating arena in which visitors will be able to watch live concerts or sports. However, some buildings will continue down beneath the waves, enabling people to view the natural underwater world around them – as well as wave to friends zooming by in their subs.
A vertical garden will provide fresh air to the underwater portion of the city, while a funnel will provide additional natural ventilation and light.
Commissioned by Chinese construction firm CCCC-FHDI, a smaller version of the project could eventually take shape off the coast of China, close to Hong Kong and Macau. And it might not be as far-fetched as we think. The company used similar technology to build a 31-mile (50km) bridge between Hong Kong, Macau and Zhuhai, according to Dezeen.
This incredible structure is partially submerged beneath the chilly waters off Lindesnes, Norway. The intriguing building is part restaurant, part research facility known as Under. According to the Financial Times, this futuristic construction cost kr70 million (£5m/$6.6m) and was created by Norwegian design firm Snøhetta, opening to the public in March 2019.
Designed with its environment in mind, the structure has literally become part of its marine surroundings as the roughness of its concrete shell works as an artificial reef, encouraging limpets and kelp to make their home.
Thick concrete walls jut from the craggy shoreline, built to withstand the pressure and impact from the waves crashing around it.
Inside, the coloured ceiling panels change from warm tones on the upper floor to cool hues on the lower floor. The design is a metaphor for the visitor's journey from land to beneath the sea.
Five metres below the surface, massive acrylic windows offer diners a view of the seabed, which changes with the weather conditions throughout the day.
Under – which means both 'under' and 'wonder' in Norwegian – was dreamed up by brothers Stig and Gaute Ubostad and is currently the world's largest underwater restaurant and Europe's first.
Within the first year of opening, Under won a Michelin star and retained it under the current head chef Bernt Sætre. According to the Michelin Guide, Sætre sources much of the fish and seaweed on the menu himself from the surrounding waters.
Moored 39 nautical miles (72km) off the mainland, Reefworld is a luxurious pontoon floating above Hardy Reef, part of the Great Barrier Reef. To get to the remote spot, guests take a three-hour scenic cruise through the Whitsunday Islands, stopping to dive and snorkel on the way.
Upon reaching the two-story, 6,000-square-foot (557m) floating platform, guests can enjoy a sundowner and a starlit supper on deck before heading down into Australia's very first underwater hotel...
Launched in 2019, Reefsuites are two residences that hang from the underside of the pontoon, 13 feet (3.9m) below water. The exclusive rooms are the only underwater accommodation available on the whole reef, which is a World Heritage-listed wonder.
Guests can lie in bed while they observe the natural life of the reef, far below the surface of the Coral Sea.
Fancy watching a giant grouper devour his breakfast while you brush your teeth? The multiple viewing windows, which include vertigo-inducing glass floor panels, allow guests to catch glimpses of some of the estimated 1,500 species of fish that live on the reef, including clownfish, parrotfish, mackerel and trevally. There are also a variety of sharks, turtles and rays.
The pontoon cost around AUD$8 million (£4.1m/$5.5m) to build and put in place. Thanks to the unique underwater suites, on-deck glamping and ocean activities, the attraction was expected to haul in an extra 60,000 visitors per year to the Whitsundays, Australia's Tourism Industry Development Minister said back in 2019.
It's hoped those tourists will contribute an extra AUD$23 million (£11.8m/$15.7m) to local businesses - not a bad return on a room (or two) with a view!
All that's visible of this incredible structure is the very top of a dome, just peeking above the surface of the ocean. This is the grand entrance to the 'Blue Garden', a 1,640-foot wide orb floating in the deep sea like a spaceship.
The futuristic bubble is a concept designed by Japan's Shimizu Corporation and it's just a tiny part of Ocean Spiral, a larger form that lies beneath the waves...
The 'infra spiral' that gives the design its name links the Blue Garden, a deep sea city, to an 'earth factory' on the sea floor, which would be used to store CO2 and extract resources from the sea floor.
The spiral would house a gondola terminal so that people living and working in the futuristic city could travel between the two hubs. As well as being used for scientific research monitoring marine life and acoustic waves, the spiral would also transport oxygen, water and electricity down to the earth factory and ocean floor resources back up to the Blue Garden.
If the concept ever came to fruition, the curved walls of the Blue Garden would house residential suites, an observation gondola and walkways.
This central tower would consist of a hotel, offices, apartments, a central plaza and multiple parks, all above a freshwater spring and a gondola station that would ferry people down to the earth station below.
The city, designed to be safe from typhoons and earthquakes, would house 4,000 permanent residents and 1,000 visitors and would become a hub for new deep sea industries, including research, tourism, energy and resource businesses.
While Ocean Spiral is a concept and there aren't any current plans to bring it to life, it does give us a glimpse into how the deep sea could solve some of the greatest challenges we face on terra firma. Shimizu calls the deep ocean "the earth’s final frontier" and believes we could provide food, sustainable energy, clean water and other resources, as well as a place to store and process CO2.
The world's first underwater villa, known as The Muraka, is connected to the Conrad Maldives Rangali Island resort by a long jetty.
Promising incredible ocean views, it was designed by architect Ahmed Saleem, who wanted to create an aquatic bedroom where you could relax and unwind under the sea.
Located 16 feet (4.8m) below sea level, the submerged bedroom is surrounded by a host of colourful marine life and the vibrant coral reef. It was built from steel, concrete and acrylic, and designed to have minimal impact on the local ecosystem.
Opened in 2018, the lower level of the villa was built in Singapore and then moved by ship to the Maldives. It was carefully submerged into the ocean so as not to damage the delicate coral reef.
Weighing in at 600 tonnes, the dwelling is held in place with 10 concrete piles that can weather the roughest of storms.
The upper level offers spectacular views across the infinity pool and private jetty. Guests can then descend the spiral staircase into their very own underwater oasis.
How's that for dipping your toes in the water?
Designed by US Submarine Structures, the stunning submerged H2ome design offers five-star luxury living 59 feet (18m) under the ocean.
Ideal for lagoons, shallow seas and lakes, the prefabricated aquatic pad is accessed by a private pier and elevator.
Encompassing 3,600 square feet (334sqm) , the underwater accommodation consists of two spacious storeys.
The top floor houses two bedrooms, two bathrooms and a lounge, while the bottom floor features a master bedroom complete with an ensuite, as well as a modern kitchen, wine cellar, bar, library and chill-out area.
The lower floor is fitted with ceiling-to-wall transparent acrylic panels, with feeding devices attached to the external walls to attract shoals of colourful tropical fish, so you'll never be without a jaw-dropping view.
US Submarine Structures can also landscape the underwater area around the H2ome, planting coral beds to entice aquatic animals and marine life. But all this comes at a price – US Submarine Structures was quoting around £9 million ($12m) for their state-of-the-art H2ome, plus installation costs.
Imagine a plush villa filled with opulent amenities – now imagine it's partially submerged beneath the surface of the water.
The Original Edition Floating Seahorse home will be a masterful feat of engineering – should it be built as planned – featuring several above-water levels and phenomenal undersea living spaces, complete with massive floor-to-ceiling windows.
Developed by the Kleindienst Group, the Original Edition was the company's first concept underwater home that paved the way for a succession of luxury designs.
Its planned location is Dubai's World Islands and Heart of Europe development, which is centred around six islands that offer a variety of European cultural experiences. Up to 50 Floating Seahorse homes will be situated at the new resort, which was originally set to open at the end of 2020 and is now slated for completion in 2026, according to Josef Kleindienst, of the Kleindienst Group.
Each Original Edition villa offers stylish accommodation spread across three levels. The main living space is located above sea level and includes a large outdoor deck for soaking up the sunshine, while a reception room on the upper deck provides panoramic vistas of the surrounding islands.
The underwater level encompasses the spectacular master bedroom and bathroom, which benefit from breathtaking views of a coral garden.
Imagine taking a long, hot bath with that surreal ocean outlook!
The larger four-room Signature Edition Floating Seahorse, which was unveiled in 2016, offers a generous 4,000 square feet (371sqm) of living space, enough to accommodate up to eight people.
Designed with families and large groups of friends in mind, the units are currently advertised for around AED 22 million (£4.5m/$6m) each, although it's unclear how many have been built.
Aimed at holidaymakers searching for a second home, each property will be packed with state-of-the-art technology and no end of sumptuous living spaces.
As with their predecessor, the Signature Edition has also been launched at the Heart of Europe Dubai resort, with the construction of more floating villas underway.
The underwater level in the Signature Edition includes two rooms, an ensuite bathroom and a sensational viewing area with floor-to-ceiling windows.
Residents will be able to marvel at the villa's coral garden and the many colourful fish it should attract.
Once completed, the Signature Edition homes will benefit from cutting-edge smart home technology, which will control everything from the blinds to the lighting.
The design's pièce de résistance, however, has to be the upper deck, featuring a Jacuzzi and a luxe outdoor living area. According to the Kleindienst Group, there are 131 Floating Seahorse villas planned for the Dubai resort.
The latest Floating Seahorse design, the Tzar Edition will be located off St Petersburg Island within the Heart of Europe development.
The grand underwater homes have apparently already sold out and are set to be sited just offshore of the idyllic heart-shaped isle.
Inspired by the opulence of Imperial Russia, the Tzar Edition villas are tastefully decadent and filled with features that only billionaires can afford.
Decked out with lots of gold accents, fine marble and quality wood finishes, the villas are bound to please the richest house hunters.
No expense has been spared when it comes to fitting out the retreats with the latest pioneering technologies either.
As well as futuristic smart home automation, the outdoor areas of the Tzar Edition are equipped with climate control to temper the searing Dubai heat.
Like the other Floating Seahorse designs, which all come with a 100-year guarantee, the Tzar Edition includes a whirlpool bath, mini bar, day beds and a cleverly hidden kitchen accessed by a sliding wood panel, not to mention some of the best snorkelling around the world on your doorstep.
Loved this? Now discover these incredible cities of the future