The Philadelphia Museum of Art -- home of the famous "Rocky" steps -- has announced a transformation led by architect Frank Gehry that will run through 2020.

philadelphia-museum-of-art_forum.jpgPhoto: courtesy of ©Gehry Partners, LLP and KX-L

Attracting 600,000 to 800,000 visitors per year, the Philadelphia Museum of Art has a collection of more than 240,000 objects spanning 4,000 years. Of note are works by Thomas Eakins and Charles Willson Peale that shed light on the history of the city and of the US, as well as the most significant collection anywhere of works by Marcel Duchamp, including his final, site-specific project, "Etant Donnés."

The redesign of the neoclassical building sets out to improve the visitor experience and to create new gallery space for the museum's collection, which grows by one percent per year. Focusing on the heart of the building, the project will see the addition of a new public space called the Forum that will provide access to areas that have been closed to the public for nearly 50 years.

philadelphia-museum-of-art_west_entrance.jpgPhoto: courtesy of ©Gehry Partners, LLP and KX-L

Additional galleries for American art (nearly two-thirds more) and contemporary art (one-third more) and a newly designed restaurant and café are among other planned features.

The result, according to the museum, will be "a seamless blend of old and new," as Gehry's team plans to work with the building's pre-existing architectural style and materials.

"I walked through the building and I saw that all you had to do was follow the yellow brick road, so to speak. It was all there, and it showed you what you could do," said Gehry of the design.

The project's first phase, set for completion in 2019, will consist of the reopening of two areas, the North Entrance and the Vaulted Walkway. Through 2019 and 2020 additional spaces will open, and the project is expected to come to a close in the summer of 2020.

The museum will remain open and fully operational during construction.