The opening date for the Four Seasons Philadelphia has been set for 12 August. The property was originally scheduled to open in Q3 2018.

The 219-bed hotel, located atop the 1,121ft (342m) Comcast Technology Center in Philadelphia’s downtown, offers views from the 48th to 56th floors.

Set above it, the spa will include seven treatment rooms and an indoor infinity pool. The 17,321sq ft facility will encompass the entire 57th floor.

The building was designed by Norman Foster of Foster + Partners as a mixed-use development that includes high-tech research and development spaces, as well as restaurants and state-of-the-art television studios for NBC.

The design, which has been planned for LEED Platinum, features a series of ‘pocket parks’ and social spaces, and is vertically stepped to create a sleek, minimalist design.

Foster + Partners won an international competition to design the building, which will be America’s tallest outside New York and Chicago.

The spa will feature a subtle crystal theme, created under the direction of Four Seasons' Verena Lasvigne-Fox, with more than 700 pounds of crystals embedded into the walls.

It will also feature a lifestyle boutique, a 30,000-gallon outdoor infinity pool and a state-of-the-art fitness centre created in consultation with celebrity fitness guru Harley Pasternak.

Christian Clerc, president, worldwide hotel operations at Four Seasons Hotels and Resorts said: “The history and culture of Philadelphia are so often expressed in the characteristic storytelling of its art and architecture.

"Now, thanks to the vision of our partners at Comcast and a world-class team of designers, architects and artists, the Comcast Technology Center stands tall as a new Philadelphia landmark – reshaping the city’s skyline and signifying a new, exciting chapter in its storied history."

View from the top – Foster's Four Seasons Philadelphia to feature 57th-floor spa