Cathedral of Saints Peter and Paul, Philadelphia vs Christ Church
Two churches in Philadelphia. Cathedral of Saints Peter and Paul, Philadelphia has no online ticket listed; Christ Church has 1 ticket or tour to book. The table and the two notes below put them side by side; the full pages have what to see, the ticket and the timing for each.
The cathedral stands on Logan Square, at the museum end of the Benjamin Franklin Parkway, and entry is free. It is a natural stop on any walk up the parkway from the city hall to the art museum, and most guided tours of central Philadelphia include at least the exterior. Tours focused on the city's immigrant and Catholic history go inside and explain the building's defensive design, which is the detail that makes it memorable.
Christ Church is in the old city, two blocks from the waterfront and five minutes from Independence Hall, and it asks a small suggested donation rather than an admission charge. Guides are stationed inside through the day and give short talks, which are included. The burial ground is two blocks west at Fifth and Arch and is ticketed separately; it holds Benjamin Franklin's grave, visible through the railings for nothing if you would rather not pay.