Cleveland, Texas, is a small town about 45 miles north of Houston. It is a popular day-trip destination for its many outdoor activities; the mild climate means that you can enjoy most (except swimming) year-round. It was a center for lumber and saw mills at the turn of the century.
The National Recreation Trail starts in Cleveland and goes 129 miles through the Sam Houston National Forest. Part of the trail is an old railway. There are no bathrooms along the trail, so bring water, toilet paper and hand sanitizer. You are allowed to camp along the trail.
The Trinity River National Wildlife Refuge has a lake and forest where you can look for bald eagles, osprey, bluebirds, snakes, frogs, white-tailed deer, coyotes and raccoons. There is also a butterfly/hummingbird garden. The refuge has portable toilets. Note that parts of the refuge are open for hunting, so be sure to stay in areas where no hunting is allowed.
The Retreat at Artesian Lakes has a spa, pool, a lake fed by artesian well water (with water slides), bike rentals, horseback riding, and fishing and boating. You stay in log cabins.