Lake Mead is a vast piece of land with a lot to offer. The whole area is more than just a body of water. There are beautiful canyons and rock formations great for day hikes and exploration. The area further from the lake almost have no trace of human civilization. Apart from the main highway, there is nothing between you and nature.
Some of the less popular trails might be difficult to locate. The trailhead are quite easy to miss. Having the actual coordinates of the trailheads could be really useful here.
Even if you don't have a lot of time to hike, check out the Northshore Summit. The hike to the top of the bluff is short but rewarding. Redstone is pretty too but getting to the summit would require some rock scrambling.