The "Narrows" is the slot canyon on the Virgin River in Zion National Park. Consistently rated as one of the top 10 hikes in the US NP system, I can't begin to describe how great this hike was. You actually hike in the Virgin River (sometimes on it's banks) with 80+ft walls on either side. If you find yourself out West in Zion NP take the extra day and spend the money on the rental equipment to do the Narrows.