City Fitness plans to open a 27,000-square foot health club on the second floor of the apartment building being developed at 12th and Market Streets as part of the East Market office, retail and residential complex.

This will be Philadelphia-based City Fitness's sixth club when it opens in the summer of 2018, the East Market project's developer, National Real Estate Development, said in a release Thursday.

The club will occupy an entire second level of the 12th and Market Street apartments, above a ground floor shared by Iron Hill Brewery & Restaurant and a Wawa convenience store, making it the East Market project's biggest retail tenant yet to be announced.