Gullfoss is Iceland's most famous waterfall, and one of the natural wonders of the world. It is in the mighty glacial river Hvitá (White river), just a few kilometers from another natural wonder, the world-famous Geysir. The enormous white glacial cascade drops 32 meters into a narrow canyon which is 70 meters deep and 2.5 kilometers long. Its spectacular two-tiered cataract hangs in the air like fine drizzle, which forms a rainbow in the sunlight. In winter it has an unusual appearance when it is garbed in ice and snow. Geysir, Gullfoss and Þingvellir all together comprise the famous Golden Circle tour.