Dyradalur valley is one of the valleys surrounding a mountainous road in South West Iceland named Nesjavallavegur (or Nesjavallaleið, Road nr.435). The road leads from the Ringroad (Road nr.1) to Nesjavellir Geothermal Power Station and Þingvellir National park, Iceland. The road winds through several mountain passes in the vicinity of mt.Hengill. This is a highly recommended alternate route for travellers on their way from Reykjavík, towards Þingvellir National park, Iceland or Gullfoss and Geysir.
The road through Dyradalur is only open during the summer months and is not maintained during the winter months due to heavy snow and icy steep hills. The area is a popular destination for hiking and mountain biking. See www.icebikeadventures.com for further info on bike tours in the area) due to it´s countless trails and stunning natural beauty of the surrounding valleys (Dyradalur and Marardalur) and mountains.