If you are looking for site-seeing or activities to do during the day while in town for the wedding, here are a few suggestions:

-Catoctin Wildlife Preserve (and zoo)

-Cunningham Falls State Park has hiking, a lake, a waterfall, and picnic areas

-Catoctin Mountain Park (National Park Service) has great hiking and camping

-Historical sites nearby include Gettysburg, Harpers Ferry, and Antietam National Battlefield