Zion’s Subway is one of the most photographed slot canyons in Utah, and most accounts treat the top-down route as the only real way to do it. The bottom-up approach trades the technical descent for an out-and-back river walk: you wade upstream through The Left Fork of North Creek, reach the iconic subway-shaped tunnel, photograph it, and walk back. No canyoneering permit needed, no rappel skills. 9 miles round trip, wet feet guaranteed.