Unlike other parts of the country, the glorious swimming pool at Balmorhea State Park in West Texas stays open year-round. The water is consistently a bone-chilling 72 to 76 degrees. There is a high dive, a low dive, and plenty of areas for picnicking and sunbathing (but not a ton of shade). The pool’s 15 million gallons of crystal-clear water gush in from nearby San Solomon Springs, making this the largest spring-fed swimming pool in the world. And because it’s au naturel, Balmorhea is ideal for snorkeling and scuba diving. You’ll often see local kids feeding schools of fat, happy catfish. The surrounding state park covers 46 acres and includes a manmade cienega, a type of desert wetland that is home to a bounty of endangered fish (Comanche Springs pupfish and Pecos gambusia among them). Balmorhea has 34 campsites, plus a sparsely furnished “retro” motel named San Solomon Springs Courts. Pack snacks and a bucket of sunblock, and have at! Park entry is $7.

9207 Hwy 17 South, Toyahvale, TX; 432-375-2370.