The Miller Theater is an excellent outdoor venue in which to see a variety of shows and performances. There is no cost to attend the theater and shows run from June to September. From a swing music revue to an academic look at 18th-century baroque Spanish music, the Miller has something for everyone. The theater is in Hermann Park; attendees need to bring either blankets or lawn chairs for seating.
The Museum of Fine Arts, located on Bissonnet Street, is another Houston favorite. The museum typically charges $7 for adult admission, but on specific holidays, such as Labor Day, the museum will let you tour its wonders for free. Take advantage of the gallery portion of the museum that houses early American and 18th-century European art. Stroll through beautiful flower gardens, and be sure not to miss the sculpture garden created in 1986 especially for the museum. This is a great family activity as it offers culture for the adults but also allows for outdoor play time for the kids.
If you're looking for a bit more of a contemporary take on your day free from labor, check out the Lawndale Art Center on Main Street. Housed in an art deco building, the Lawndale features only local modern artists with an ever-changing rotation of pieces. It is a nonprofit organization, accepting donations only, and is a wonderful way to support local artists. This is, except maybe for teens, not a kid-friendly outing, because the pieces often focus on adult themes.