Zion Narrows (hiking), Utah
This dramatic gorge cutting through Zion National Park claims a close second place behind the Grand Canyon for sheer, jaw-dropping canyon beauty, yet draws just over half of the more famous park's annual crowds. The path through the gorge—home to some of the world's deepest slot canyons—alternates between gaping, quarter-mile-wide stretches and narrow, 20-foot passageways, and runs directly through the Virgin River's bed—which means hikers who want to go the distance will have to ford waist-deep water from time to time. Still, Zion's fans believe it's worth the wade to stare up between the 2,000-foot-high sandstone walls, lined with lush hanging gardens, streaming with flutes of water, and bouncing with beams of red-orange light.
Book a Trip: If you're not the type to wander through canyons on your own—or all that keen on waist-deep wading—the pros at Zion Rock Guides lead beginner-level full-day (dry) hikes that include a stop for lunch and ice cream at the in-park Zion Lodge (zionrockguides.com, from $90).