Formed on the Mid-Atlantic Ridge less than 18 million years ago, Iceland remains a hot spot of geothermal activity with innumerable hot springs and geysers, as well as glacial rivers, thundering waterfalls and razor-sharp lava fields. The island has fewer than 330,000 inhabitants, and it is possible to drive for hours on the main 830-mile Ring Road without seeing a soul, although visitor numbers have surged since 2010. Travelers invariably pass through Reykjavík, the capital, which is filled with colorful buildings and quirky modern designs. The principal reason for a visit to Iceland, however, is its great outdoors. From Reykjavík, three of the country’s most spectacular natural wonders can be visited easily in a day’s drive around the popular “Golden Circle.”