If you have the time and a car, it’s about a 1/2 hour drive from Las Vegas to the Lake Mead/Hoover Dam area, which is very much worth seeing. It’s also the site of a wonderful run: the Historic Railroad Tunnel Trail, which runs 3.5 miles one-way between the Lake Mead Visitor Center and Hoover Dam. The original railroad was used to transport materials in the building of Hoover Dam. There are five tunnels and numerous sites along this flat, gravel trail. The trail is part of the 32-mile River Mountains Loop Trail.