Our personalized, half-day Golden Circle tour included stops at Langjökull, Gullfoss, Strokkur, Þingvallavatn and Þingvellir. Although we'd visited more impressive geothermal areas and waterfalls during our two week holiday in Iceland, we really appreciated the stop at Þingvellir, site of the world's oldest parliament and where the mid-Atlantic Ridge is visible above sea level!