The waterfall Öxaráfoss (The waterfall in the Ax River) in the ravine Almannagjá at Þingvellir is one of the best-known waterfalls in Iceland, at least among Icelanders. Like everything related to Þingvellir and Almnnagjá the waterfall has a sentimental reference and historical value. It is an important place in our most precious and sacred place Þingvellir. It is positioned inside Almannagjá in the Mid-Atlantic Ridge. The waterfall is rather small, only about 20 meters high, but is an important part of the overall natural wonders in the Þingvellir National Park. Depending on the season, the waterfall may differ in volume as the source, the river Öxará or Ax river, is quite different from one season to the next.
Not entirely the work of mother nature
Interestingly the waterfall Öxarárfoss is actually a human-made waterfall. As strange as this may sound geologists and historians have discovered that the river Öxará was moved hundreds of years ago, to channel the water into the ravine Almannagjá in the ninth century. The purpose was to provide water for the members and visitors of the Icelandic parliament Althingi in the 9th century. This was documented in the saga Sturlunga written in the 12th and the 13th century. The name, according to folklore, came from an Ax that killed a notorious and a very unstable female troll famous for killing and terrorizing visitors, inhabitants and travelers in the Hengill area not far from Þingvellir. Long after the blade was put into her back, between her shoulder blades, it surfaced near the place where Öxarárfoss is now. According to another folklore, the river changes to wine on new year's eve. If true you should be able to sit by Öxarárfoss and drink good wine from the waterfall until midnight when the river changes back to wine. Not something we recommend as king winter has all the power at Öxarárfoss and Þingvellir at that time. He might be drinking from the waterfall and probably quite drunk.
Access is relatively simple but requires a short walk
When driving from Reykjavík, you take the Ring Road Nr. 1 through Mosfellsbær and take a turn west on Þingvallavegur Nr. 36. When you reach a sign that says Öxarárfoss near the entrance to Þingvellir National park you park the car. You can also go to the Service Center for Almannagjá and walk through the riff to Öxarárfoss.
Below is the location of Öxarárfoss waterfall on the map of Iceland