Golden Circle is a trip around the city exploring the area's geology. There are three primary stops that you can see while on this route Pingvellir National Park, the Gullfoss waterfall, and the Haukadalur geothermal field. There are a few minor stops as well, and covers about 300 Km.
You can choose either tour operators or go by yourself on the Golden Circle by renting a car. It covers about 300 km and can take anywhere from 4 - 6 hours. The stops are Pingvellir National Park, the Gullfoss waterfall and the Haukadalur geothermal field which has geysers. Other minor stops are Kerid volcanic crater, Skalholt cathedral and geothermal power plants at Nesjavellir and Hellisheioarvirkjun.