Mulagljufur Canyon
The hike is renowned for being one of the most scenic in Iceland. In fact, at all times you will be able to see a glacier, the ocean, the gorge and stunning waterfalls. As you walk up following the wooden sticks, you'll have to cross a stream before finally reaching the picture-perfect view of the Mulagljufur Canyon.
Try this 3.6-mile out-and-back trail near Öræfasveit, Eastern. Generally considered a challenging route, it takes an average of 2 h 18 min to complete. This is a very popular area for birding, hiking, and running, so you'll likely encounter other people while exploring.
I suggest getting on the trail EARLY (Have it all to yourself!) Before 8am I would recommend.