Described by LAVA founder Alexander Rieck as an "ultra-luxury upside-down skyscraper," the building will contain hotel and retail spaces as well as residential apartments and "innovative hubs". It will be located along the Gulf of Aqaba coastline in Saudi Arabia.

It will feature a floating marina that will be located in the sea next to the mountain range and will be the first point of access for visitors.

To enter Aquellum itself, visitors will go on a "specially designed vessel" that will travel on a hidden underground canal. This will open up into what the studios describe as an "underwater open square".

"Aquelleum is an ultra-luxury upside-down skyscraper," Rieck said. "The facade's facing inwards instead of facing outwards."

"Things are inside-out and upside-down," he continued. "Normally architecture is focused to the outside."

The building will be centred around a 100-metre-tall central void that rises from the underwater square and is surrounded by a courtyard with walkable paths.

Visuals show a large, open concrete building with geometrically shaped balconies protruding from the walls, as well as deep cutouts that will house terraces and patios, ponds and indoor waterfalls.

"It becomes this sort of magic cube around which everything plays out," Name Architecture founder Nathalie Rozencwajg said.

The only exterior part of the building, the roof, will contain a space described as a cloud garden. Renders show planted pathways arranged above the void, with the water below visible through gaps in the ground.

The different levels of the skyscraper will be connected by the boulevard, a path that winds its way through the courtyard.

Aquellum will also feature a space named The Generator, which will be dedicated to research labs.

"It's an experiential space that will change you forever," Rozencwajg said. "It's a metaverse that you can physically experience."

"You have residences, you have hotels, cinemas, museums and The Generator, which is this research lab that will attract creators to come and interact and new ideas to emerge," she continued.

Aquellum is the latest Neom project to be unveiled in the Gulf of Aqaba and follows on from luxury hotel trio Leyja, hexagonal-pillar hotel Siranna, jagged skyscrapers Epicon, the Ricardo Bofill Taller de Arquitectura-designed Utamo, and coastal yacthing town Norlana.

The projects are the latest to be announced as part of Neom, which is one of the world's largest and most controversial developments and includes plans for a 170-kilometre-long city called The Line.

It has been criticised on human rights grounds, including by human rights organisation ALQST which reported that three men were sentenced to death after being "forcibly evicted" from the Neom site.

Last year experts from the UN Human Rights Council expressed "alarm" over the imminent executions. Saudi Arabia responded to the UN by denying abuses had taken place.

The visuals and video are courtesy of Neom.