Athenaeum of Philadelphia

With a focus on conservation and propagation of historic plants, this garden features one of the most important rose collections in the nation, preserved from the 19th century! - visitPA

go see an original stamp tax from the era of Revolutionary War in this amazing 18th century archive/library - Marc Brasof

This place is a hidden gem in Philadelphia. Entry is $8/$5. In spring and in fall it can be cool to go there, sit down in the garden and relax. In the summer it can be a bit too hot inside (No AC) - Enrico

Very big, plenty of seats, greenery, and bit overflowed with wild life - Henri L'île