London's BURLINGTON ARCADE first traded to the public in 1819. It opened with seventy-two, 2-storey units. Over the years, some of these were combined. Today, there is a total of forty.
Photo from Wikipedia / "Solipsist"

The ROYAL ARCADE opened, in Melbourne, Australia, in May 1870. There are presently thirty-four shops in the complex, which was renovated between 2002 and 2004.
Photo from Wikipedia / "Biatch"