The Appalachian trail is hiking trail in the Eastern US stretching from the mountains in Georgia all the way to Maine.
Have you ever hiked it?
No, but at least over 2 million people are said to have hiked it. 
I've been on it for about an hour, but that's the extent of my experience with it.
Wow, thats crazy, I didn't know it was longest hiking only trail in the world.
Yes, it sure is. It's beautiful too. I've only been on it in Georgia.
Appalachian Trail
The Appalachian National Scenic Trail, generally known as the Appalachian Trail or simply the A.T., is a marked hiking trail in the Eastern United States extending between Springer Mountain in Georgia and Mount Katahdin in Maine. The trail is about long, though the exact length changes over time as parts are modified or rerouted. The Appalachian Trail Conservancy describes the Appalachian Trail as the longest hiking-only trail in the world. More than 2 million people are said to take a hike on part of the trail at least once
ridges and filled the valleys to some extent. The glaciated regions are usually referred to as hill country rather than mountains.
The Appalachian region is generally considered the geographical divide between the eastern seaboard of the United States and the Midwest region of the country. The Eastern Continental Divide follows the Appalachian Mountains from Pennsylvania to Georgia.
The Appalachian Trail is a hiking trail that runs all the way from Mount Katahdin in Maine to Springer Mountain in Georgia, passing over or past a large part of the Appalachian system. The International