A battle is brewing in San Francisco’s Marina District over the fate of the Palace of Fine Arts rotunda and the adjacent structure that formerly housed the Exploratorium.

Designed by Bernard Maybeck, the Palace of Fine Arts is a historic remnant of the 1915 Panama Pacific International Exposition, but only the Beaux Arts rotunda and colonnade are designated landmarks. San Francisco’s Recreation and Parks Department is currently vetting long-term tenants for the vacant shed-like building.

In June, the commission issued a Request for Concept Proposals and received seven proposals, which included both for- and nonprofit ideas including a hotel, a recreation center, arts and technology lab, a food pavilion, and a museum. This month, the commission narrowed the field to three and a final selection is expected by summer.

At issue is whether or not the 144,000-square-foot palace, including the former Exploratorium space and theater will remain an arts and education center open to the public, or if it would house a more commercial enterprise such as a fitness club or hotel. Advocating for the former, S.F. resident Kristen Selberg created an online petition asking for Mayor Ed Lee and the Rec & Parks to preserve the Palace of Fine Arts for cultural use.

“These things are important to San Franciscans, especially with what we’re dealing with right now, such rapid change in The City that’s not necessarily for the best,” Selberg told the San Francisco Examiner, conveying a sentiment familiar to many in San Francisco who feel that Mayor Lee is a bit too cozy to private interests. “San Franciscans are just begging to hang on to something for themselves and for The City.”