This past weekend, we visited a few of these, starting with Washington Square. This square is basically a small park centrally located in the Society Hill section of Philly. The most famous portion is the Tomb of the Unknown Soldier, which is dedicated to the memory of those who gave their lives during the American Revolutionary War.
A short walk from here is the Magnolia Garden. Unfortunately, when we came only 2 Magnolia flowers were still in bloom. This garden felt quite plain otherwise.
Across the street from this is the Rose Garden, where we saw absolutely no Roses, which was quite disappointing. It seems the maintenance on these 2 gardens is quite minimal, which is unfortunate since there is so much potential for them.
Further down the street is the 18th Century Garden, which was definitely the nicest and most up-kept of the three. Despite being small in size, this garden does have a very peaceful and simple tone to it that makes it quite enjoyable to see.
The final section we visited on this trip was Welcome Park, which I honestly don't think should even qualify as a park. While a nice statue of William Penn is centered in the park, it's basically all concrete, and unfortunately features some of Philadelphia's homeless as its regular residents (at least that is what we saw when we visited on a Sunday morning).