Reykjavik (1)The Golden Circle tour (Þingvellir – Geysir – Gullfoss) includes a visit to Þingvellir, which is the world’s oldest democratic parliament founded in 930. Þingvellir, located by lake Þingvallavatn, the largest lake on the island, is now a national park. Continue to the great Geysir area, where you will see one of the most active geysers in the area. From there continue to Gullfoss (Golden Waterfall), where you will see thousands of tons of icy waters thunder majestically down in a double-fall into a deep gorge.