"A visit to Boulder City is incomplete without a trip to Lake Mead and the Hoover Dam. One way to take in both sights is to journey along the Historic Railroad Tunnel Trail. An easy walk or a brisk bike ride, this 3.7-mile trail used to bear railroad tracks for trains to carry stone to the dam site. Now a flat, broad walkway, the trail hugs the side of a cliff overlooking the blue water of Lake Mead. Pass through the five tunnels to reach the top level of the Hoover Dam visitor parking area, which gives way to an awe-inspiring view of the historic dam below. If you’re going in the summer, bring lots of water and sunblock. The tunnels offer shade from the sun but they get hot by the afternoon." - Janna Karel