The Texas Historical Commission is celebrating National Preservation Month by offering free admission at state historic sites on Sunday, May 15. Celebrate your local history and visit a state historic site for free. See below for the list of participating sites.  From military strongholds to house museums, plantations, and Native American settlements, these historic sites offer visitors the opportunity to truly experience the real places of Texas and the stories they preserve. Read everyday stories from the sites at the Historic Sites blog. For more information, please visit http://www.thc.state.tx.us/hsites/hs_free_day.shtml.