Finnish Modernist architect Alvar Aalto accidentally invented the skateboard bowl with a 1930s swimming pool design, according to a US skateboarding magazine and a Finnish newspaper.

Alvar Aalto's seminal 1939 Villa Mairea in Noormarkku, Finland, features the world's first kidney shaped swimming pool and was the precedent for a rash of similar designs in the US, according to Transworld Skateboarding.

The pool is also significant for its rounded floor and change in depth from one end to the other, creating a bowl-like effect at the "deep end" that would become key to an explosion of illegal back-garden skateboarding sessions and trick developments during the 1975 Californian drought.

Transworld Skateboarding broke into the pool to skate it for the first time after spotting an article in Finnish newspaper Helsingin Sanomat, and published photographs from the session this week.

"It might be the swimming pool that changed the history of skateboarding," said Helsingin Sanomat. "Until then, swimming pools were traditional rectangles, but the pool at Villa Mairea doesn't have any angles in the pool."

The newspaper linked the Villa Mairea pool to the 1948 Donnell Garden in Sonoma, California. It was designed by landscape architect Thomas Church, with a young Lawrence Halprin and architect George Rockrise, for the home of Dewey and Jean Donnell. The garden quickly became famous, thanks to its unusual use of forms – including a large kidney-shaped pool.

Church was Aalto's friend and was heavily influenced by his work, moving away from sharp angles in favour of more rounded shapes after a meeting the architect during one of his visits to the US.

Helsingin Sanomat spoke to contemporary landscape architect Janne Saario, who has designed a number of skateparks in Finland and elsewhere, and has studied Aalto and Church's pools. "It's like a direct copy," he said.

The Donnell Garden pool was widely replicated across California, becoming an iconic symbol of the "good life". During the 1975 drought, many of these pools were left empty as part of widespread preservation efforts.

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The empty bowls proved fertile ground for skateboarders, who found the curved shapes ideal for developing tricks, and broke into gardens illegally for skating sessions. Bowls have since become a key component in skatepark design.

"They soon were found by skateboarders and became their new playgrounds," explained Transworld Skateboarding. "The tricks invented in the 1970s in the empty swimming pools of California are still being done 40 years later, and skateparks still use those similar concrete basins — whose role model is likely to be found in Villa Mairea."

The Villa Mairea was commissioned by Finnish arts patrons Marie and Harry Gullichsen, who gave Aalto and his wife and business partner Aino a completely free hand in the design, telling the duo to treat it as an experiment.

The interiors were designed by Aino, while the structure and its accompanying pool represent a key moment in Alvar's move away from a more rigid form of Modernist functionalism into the exploration of more organic shapes and material combinations.

Alvar Aalto, who died in 1976 at the age of 78, is one of the most famous Finnish architects and designers in history. He designed his own museum in his hometown of Jyväskylä, which was recently the subject of an international competition to design an extension to connect it to another Aalto-designed building. His other key buildings include the Säynätsalo Town Hall (1952), and a range of public and university buildings in Helsinki.

A restoration of Aalto's Viipuri Library in Vyborg, Russia, received the World Monuments Fund/Knoll Modernism Prize for preservation award two years ago.

He also set up the furniture company Artek with Aino in 1935, and the company's best-known and much replicated designs include the three-legged Model No 60 stool.

In 2014, the Vitra Design Museum in Weil am Rhein hosted a major retrospective exhibition of his work.