Frank Gehry and the Philadelphia Museum of Art (PMoA) have unveiled a new masterplan for the 90-year-old museum site in America.

Known for his famous cultural projects such as the Guggenheim Museum in Bilbao, Spain, Gehry’s latest designs for PMoA have been revealed in a new exhibition – Making a Classic Modern: Frank Gehry’s Master Plan for the Philadelphia Museum of Art – which is now open to the public.

The most daring aspect of the $352m (€257m, £205m) scheme appears to be the proposed creation of a 7m (23ft) wide opening in the now infamous “Rocky steps” leading up to the east entrance of the museum. This will provide access for several of the new underground galleries that Gehry has masterminded.

The steps became an important tourist attraction following their debut in the first Rocky film in 1976 and continued to feature in all of its sequels. Visitors often climb the steps to recreate Stallone’s infamous apex move.

Overall, the project is planned to be completed by 2028, Gail Harrity, the Museum’s president and chief operating officer, said: “Given the ambitious scope of the plan, it has been designed in separate phases that can be implemented as funds become available.”

Ultimately, the expansion and renovation of the museum will be time consuming and costly, but with a predicted increase of 169,000sq ft (15,700sq m) of gallery space, the interior of the building will be completely transformed, making it more accessible and open to the public.