Gullfoss (The Golden waterfall) on the glacial river Hvita (White river) is Iceland's most famous waterfall,  dropping 32 metres into a narrow canyon which is 70 metres deep and 2.5 kilometres long. Gullfoss is a two-tiered waterfall, and when the sun is shining (sadly, it was not during my visit), you're likely to see a rainbow through the spray. 

Years ago, Gullfoss was part of the nearby farm Brattholt owned by the farmer Tomas Tomasson and his daughter Sigridur Tomasdottir. Foreign investors wanted to buy Gullfoss for hydroelectric development. The farmer and his daughter took the case to the parliament, and Sigridur threatened to drown herself in the waterfall if the deal went through. The government intervened and purchased the Gullfoss. A memorial to Sigridur stands above the falls.