A collection of lithographs by Salvador Dalí was recently found forgotten in a London garage.

According to the British auction house “Hansons Auctioneers,” ten lithographs by Salvador Dalí are set to go up for auction after being discovered in the garage. The artwork was found along with five other lithographs by French artist Theo Tobiasse in a garage in the Mayfair district of central London.

“This is an amazing find,” said the auction house’s deputy director, Chris Kirkham. “I was called to assess some antiques at a client’s home. During the visit, the seller took me to his garage, and behold, this treasure trove of surrealist lithographs—15 in total—was revealed,” he continued.

“They had been hidden and forgotten for about 50 years. It feels quite surreal. You never know what you’re going to uncover on a routine house visit,” he emphasized.

The owner of the artwork had bought the lithographs for £500 (around $650) during the closing of a gallery in central London in the 1970s. He had intended to hang them on his walls but never did, resulting in them being forgotten in the garage.

“They came to light when the seller was clearing out. He’s looking to retire and move abroad,” Kirkham added.

The collection is expected to be auctioned on September 30, with estimates ranging from £300 to £500 for each Dalí work and from £100 to £300 for each Tobiasse lithograph, according to ARTnews.