It’s rare grab in Kowloon, the most populous area in Hong Kong. The single parking space is inside Sun Hung Kai Properties’ luxury development, Ultima, where parking spaces now cost over twice as much per square foot as the apartments.

A couple who live in the building sold the spot to an unidentified buyer.

The record-breaking parking spot cost $5,663 per square foot, while the average price per square foot for a flat in Kowloon is $2,083.

Although pricey, the parking spots at the complex—at nearly 135 square feet—still sell for much less than the 1,911 square-foot four-bedroom apartments, which cost around $12.5 million.

Last year, when the previous record for most expensive parking spot was set at $660,000 in a different part of Hong Kong, Dorothy Chow of Jones Lang Lasalle, an investment company specializing in real estate, told the South China Morning Post that the parking space market was overheated.

Buyers and sellers alike are looking to capitalize on the limited availability of parking, and investors in parking garages have been flooding in.

In fact, parking spaces have been outperforming home prices for 12 years. According to the South China Morning Post, prices for parking in Hong Kong rose 270% between 2005 and 2017, while home prices rose 256%.

Chow said that an apartment is a safer investment, because if the economy slowed, people could save money by choosing not to drive, but they would still need a place to live.

Each day, people use some form of Hong Kong’s celebrated public transportation about 12.7 million times. That number may continue to rise due to the increasingly inaccessible prices of parking in the territory.