It's almost too good to be true, and we might regret giving this away, but Sheldon Lake is honestly one of the best kept secrets in Houston. If it weren't for the sound of the nearby industry, you might think you'd stumbled onto some Precambrian swamp. The terrible lizards are still there (in the form of lake-dwelling alligators), but the reservoir is also home to a large rookery of migrating and nesting birds, making it a popular destination for kayakers. A boardwalk on the lake gives a decent view of the nesting trees on islands across the water, but you'll need your binoculars. The real treat is to head to the visitors' center on the east side of the lake. Once part of a fish hatchery, each pond is now its own separate, semi-wild ecosystem (the alligators like to nest here, too). Some are overrun with water lilies and lotuses with lily pads the size of large pizzas. In addition to the nature stuff, the park plaques also describe how the entire center was built with environmentally friendly details such as reclaimed wood and solar panels. It's a great spot for a picnic. Not to miss: the massive viewing platform that overlooks the lake, the industry of east Houston, downtown and more.