Complex sentence: Despite its official address on Fifth Avenue, the building is actually located a short distance east on 86th Street, offset from Fifth Avenue by the Neue Galerie New York, which abuts its western facade.
Split into simpler sentences: Despite its official address on Fifth Avenue, the building is actually located a short distance east on 86th Street. While the building possesses a Fifth Avenue address, it is actually separated from it by the Neue Galerie New York, which abuts its western facade.