Traveling the 117 miles (189km) from Iceland's Golden Circle to the southern village of Vik is best done by self-driving in order to allow for maximum flexibility and exploration opportunities.
It is possible to arrange for a private tour to view many of the south coast highlights, including the Golden Circle along the journey to Vik. The Golden Circle includes three main highlights, Thingvellir National Park, where you can snorkel between two tectonic plates, Gullfoss, and the Geysir Geothermal area. If driving, it would logistically make sense to do Thingvellir first, followed by Geysir and Gullfoss (in either order) before heading towards Vik.
For a more detailed look at some of the major attractions on this route, check out the Best of Iceland's South Coast & Golden Circle. Plucking some of the ideas from this itinerary will have you at the foot of famous waterfalls, Seljalandsfoss and Skogafoss, marveling at Dyrholaey, and seeing Reynisfjara black sand beach, in addition to the Golden Circle, of course.
Duration: 6-8 hours
Depending which stop travelers depart from, driving directly from the Golden Circle to Vik should take approximately three to three and a half hours, however, it is highly recommended to allow extra time for exploring stops along the way. There is an option to take either Route 35 south to the Ring Road (Route 1), or Route 30 south to the Ring Road (Route 1). They both take about the same time, however, the first option passes by Kerid Crater, and the second option passes by the natural hot spring, Hrunalaug.
After getting your fill of the Golden Circle, take some time to explore on foot, by hiking in Thorsmork or above Skogafoss, or venturing to Seljalandsfoss' neighboring waterfalls, including Gljúfrabúi, hidden in a cave. Once near Vik, make sure to check out the basalt rock columns at Reynisfjara beach.
By Private or Group Tour
Duration: 10-12 hours
It would be possible to hire a driver and make the journey on a private tour within a full day if based near one of the Golden Circle highlights, but spreading it out over two days would be a little more relaxed for optimal enjoyment. Since most group tours depart from the airport in Keflavik, or downtown in Reykjavik, it wouldn't be possible to start and end in the Golden Circle.