YEAR-ROUND TOUR: Take in the highlights of Iceland's famed Golden Circle and much more with this 3-day group tour, which starts and ends in Reykjavik. See the plunging waterfalls of Gullfoss, Seljalandsfoss and Skogafoss, admire the erupting Strokkur gesyser and explore Thingvellir National Park. In winter, hike on Vatnajokull Glacier and search for the Northern Lights. In summer, explore a fascinating natural ice cave.