The hottest fitness amenity in New York’s luxury buildings isn’t some high-tech piece of gym equipment—it’s none other than an old-fashioned squash court. Luckily for the residents of the Lower East Side condos at Extell-developed One Manhattan Square, the waterfront tower’s 50,000 square feet of indoor amenities include an in-building court, where residents can enjoy a game whenever they feel so inclined. Better yet, the building offers opportunities for players to join an intramural team with their neighbors or perfect their technique with lessons from a professional squash instructor.