Mark Twain called it "one of the strangest freaks of nature in any land." But we prefer to call it a high-desert sea. Mysterious, tranquil, and ancient, Mono Lake is the second oldest lake in North America and a vital habitat for millions of migratory and nesting birds. It's famed for its bizarre, salt-white "tufa" towers, rising up from the lake like craggy fingers pointing skyward. These limestone formations prominently appeared in the 1940s, after Southern California began tapping the lake. Get up-close to the ethereal "tufas" by paddling right to them. The Mono Lake Committee and Caldera Kayaks rent canoes and kayaks and lead guided tours, elaborating on the lake's history, controversy, and peculiar mystique. And don't worry if you fall out of kayak (a highly unlikely occurrence): the lake's vigorously salty water will help keep you afloat. All the more reason to wonder what timeless secrets lie beneath….

The Mono Lake Committee (760-647-6595) offers canoe tours starting July 5 through the summer. The cost is $22 per person. Caldera Kayaks (760-934-1691) leads four-hour kayak trips on the lake for $75 per person most weekends through the summer. For either trip, call ahead to reserve.