Ellsworth Kelly is having a moment. Well, another one. In honor of the artist's 90th birthday next week, a number of museums are spotlighting his work, among them The Barnes Foundation in Philadelphia. On display till September 2nd, Ellsworth Kelly: Sculpture on the Wall features his influential monochrome paintings (above) as well as the massive Sculpture on the Wall centerpiece, which is having its own milestone moment. Originally installed in the Philadelphia Transportation Building, it’s the first time the work has been back in the City of Brotherly Love since it was removed and brought to New York in 1998.