It’s a turning point for 590 Madison Ave., the black granite tower at East 57th Street with a bamboo-filled atrium that attaches to Trump Tower.

RXR and Elliott Investment Management purchased the 42-story, 1 million square-foot tower last year from longtime owner State Teachers Retirement System of Ohio for nearly $1.1 billion — the first Manhattan office property to break the billion-dollar sale threshold in three years.

Scott Rechler-led RXR, the managing partner, set about preparing the former IBM tower for the future with an extensive upgrading. It included a new, 25,000 square-foot tenants’ amenity complex on the third floor called the Madison Avenue Club.

With design help from Gensler architects, RXR created a “social and wellness hub” including a 2,800 square-foot outdoor terrace-lounge. The program also brought boardroom and conference room space and a cafe and bar.

The redesign is programmed by the owner’s RXO program, which sets a high hospitality standard. There’s also a new public art installation.

Tenants include Apollo Global Management, Schoenfeld Strategic Partners and LVMH. About 100,000 square feet of office space remain available, according to RXR managing director Bill Elder, who let Realty Check tour the tower’s vacant floors with spectacular Midtown views and column-free floors.

Elder wouldn’t comment on the future of the former Bonhams ground-floor space which the auction house left for 111 W. 57th St. last year. We suspect it’s because the space might be reconfigured as part of an overall retail-space reconfiguration.