underground, river, cave, mexico, crystal, clear, water, hiking, swim, limestone, adventure, nature, pillars, maya, vacation destination, holiday destination, wetsuits, helmets, dark, flashlights, shield, stream, walk, sport, flashlight, helmet, district, travel, lamp, amerind, armor plate, water sport, plate, electric lamp, sedimentary rock, rock, diversion, metro, column, undertaking, work, north american country, subway, hike, protective covering, railway, swimming