Big Bend National Park's The Window Trail. The trailhead is located just below the Chisos Basin campground. The entire trail is great fun to hike, but we especially like the view of the desert from "the window" (above) at the end of this out-and-back trail.
This is what the park's website says about the trail:
Difficulty: Moderate; Distance:, 5.6 miles round trip
Begin at the Chisos Basin Trailhead
This trail descends through Oak Creek Canyon to the Window pour-off
which frames panoramic desert vistas. During wetter periods Oak Creek
may be flowing, and must be crossed several times. Use caution on this
trail: the top of the Window pour-off is slickrock with no railings, and
the return hike is uphill.