Parris Island is the east coast training center for male U.S. Marine Corps recruits and the nationwide training center for female Marine recruits.  What many people don't know is that it is an open base, where the public can enter and visit.  You need to have your drivers license and the vehicle registration and insurance papers to show the gate guards.  Since recruit graduation is held on most Fridays, it can be busy that morning ... as well as Thursdays which are "Family Day". 

Parris Island has a wonderful museum, which is open 10AM-4:30PM seven days a week.   It's full of displays and history of the U.S. Marine Corps, but it's interesting for all ages.  Best of all, admission is free.   There's a gift shop at the Museum offering Marine-related items and logo items. 

The historic French & Spanish colonial sites of Santa Elena and Charlesfort are also located on Parris Island.   Worth a visit if you're into history and archaeology. 

There's also a golf course, and a self-guided driving tour.