Museum
A very nice art museum in a pretty nice city - bonus: run the Rocky Steps https://philamuseum.org/
Botanical Gardens
A beautiful botanical garden on one of the nearby historic duPont estates. On rainy days there is an expansive indoor conservatory to spend hours exploring. https://longwoodgardens.org/
Museum
The wonderful network of public museums spread throughout Washington, DC. A great time to take a train in for the day and go Smithsonian-Hopping! The American History Museum and Air and Space Museum are favorites, but please let the bride know if you make it to the Postal Museum - It's been on her bucket list for years. si.edu/museums
Walkable Downtown
A quaint town full of Antique Shops, Good Coffee, Live Theatre, Historic Landmarks like the Concord Point Lighthouse and Lafayette Trail, a Duck Decoy Museum, Pleasant Boardwalk, Victorian Architecture, and more. A splendid place to spend the day!