Almannagjá is a gorge within Þingvellir National Park, which marks the edge of the North American tectonic plate. It is possible to hike through and has a beautiful waterfall within it.
Almannagjá marks the boundary of the Mid-Atlantic Rift, which runs through Iceland. This rift is the space between the North American and Eurasian tectonic plates.
Nowhere in the country is this remarkable feature more distinct than in Þingvellir National Park. At different points within it, it is possible to see both cliffs that mark the ends of the continents, and when driving through it, you descend one of them and ascend the other.
The movements of the tectonic plates as they slowly pull away from each other give the park many distinctive features. It is littered with ravines, many of which are filled with crystal clear spring water (the most famous of these being the snorkelling and diving site Silfra) and it is coated in lava rock.
The movement of the plates also created Almannagjá. As the North American plate pulled west, it could no longer sustain its weight, causing what used to be the edge to break free of the continent in an earthquake. This left the Almannagjá gorge between the two segment.
The gorge varies in width, but at several points can be walked through. A waterfall tumbles in one part of it, called Öxaráfoss, which can easily be reached on foot.
History of Almannagjá
Almannagjá gorge has witnessed a great deal of Icelandic history. This is because Þingvellir itself was the original site of the world’s longest-running, ongoing parliament, the Alþing.
The lawspeakers of the Alþing would stand on a rock above Almannagjá gorge to read out the laws of the day to thousands of people, who would come annually to settle debates, exchange news, represent their families and clans (in the earliest days), and battle for dominance.