I love a scenic road-trip! One of the greatest short drives in America is Saddle Road, which crosses between the dry and wet sides of the Big Island of Hawaii, across broad lava flows and the saddle between Mauna Loa and Mauna Kea, the world’s largest and tallest mountains respectively (base of Mauna Kea is 19000′ below sea level; the part above ocean is 13796′ high). The drive is best done on a clear day, especially in the morning as it often clouds over in the afternoon. It’s a windy road but of good quality. It used to be that not all car rental companies allowed you to take your car rental across it, but the road is so good now it isn’t a practical problem anymore (but do check with your rental company before you try it). It’s fun to see the changing vegetation as you climb the mountain: pastureland and patchy forest on the west and rain-forest on the island’s wet east side, and desert vegetation on the saddle. The road also provides access to the astronomical observatory at the peak of Mauna Kea.
Here are a few views from the Saddle.