The Zion Narrows are part of the canyon of Zion National Park . The Narrows are located in the Virgin River, which crosses Zion National Park.
The Virgin River
The Narrows are basically the most narrow section of the Zion Canyon. When hiking The Narrows, you are actually hiking the Virgin river. There isn't a hiking trail around the river so you can be sure to get wet feet when hiking the Zion Narrows.
Temple of Sinawava
Like most people me and my friends started our hike at the Temple of Sinawava which can be accessed via the Riverside Walk. From Temple of Sinawava you can hike The Narrows upstream. The Narrows are pretty long so you can basically hike The Narrows as long as you want.
Check out my video of me and my friends hiking The Narrows below.