The historic site is a replica of the 1802 American fort that was on site. The historic fort area contains 2 barracks, 3 block hourses, officer quarters, well, stockade along with a fraise fence. The site also has the archaeological outline of the 1757 French Fort. There is also a visitors center/office complex along with an area for the museum.

Actual re-creations of pioneer life of the 1700s during the annual Fort Massac Encampment and several living history weekends each year bring the past to life, letting you experience it yourself.
http://dnr.state.il.us/lands/landmgt/PARKS/R5/frmindex.htm#Events
http://www.nps.gov/history/nr/travel/lewisandclark/mas.htm