SL Green Realty Corp. is a real estate investment trust that primarily invests in office buildings and shopping centers in New York City. As of December 31, 2019, the company owned 43 properties comprising 14,438,964 square feet, and is reported to be "New York City’s largest office landlord". Notable properties owned by the company are One Astor Plaza, One Vanderbilt, 461 Fifth Avenue, 810 Seventh Avenue, 919 Third Avenue, the Pershing Square Building, and Random House Tower. Wikipedia