Really cool place, but be aware that the hike from the left side is EXTREMELY dangerous. Please don't do it. Came on a day with good weather, so dirt was soft and dry. As in too soft and dry. Took an unlucky step while making my way up on the left side where the path was very narrow and steep, and the ground completely crumbled underneath my foot and I went down on an uncontrollable slide a good several meters. It was terrifying. Was able to hold onto nothing since it was all loose dirt. Miraculously, and I really mean miraculously, right as I was sliding to the very edge, I was able to get hold of a small rock. It still came out of the dirt from my pulling, but it was enough to slow me down so that I could finally stop before I fell off. Anyways, very scary, the warning sign significantly downplays the real danger (all it says is "very steep don't hike in muddy conditions"), the left side is absolutely not worth it and in my opinion that path should in no way be open to the public, especially in the way it is currently maintained. There are no safety barriers whatsoever. Just do this hike as an out-and-back on the RIGHT side only (the side closest to the road). The right side is much easier and makes the hike worth it, otherwise it's very much not worth the hike.

And to be clear: no hiking poles would help with the worst parts on the left, to get past the steepest part you will need both hands to stay low and scramble up with the very minimal rocks in the ground you can come into contact with. And turning back at the point where you realize "oh s*** this is so much worse than I thought" is too late / very very dangerous because at that point you would have already passed a lot of very steep parts of the path and in my opinion would have had an even greater risk of slipping down in an uncontrolled way if you had tried to turn back. For me it was a point of no return and the only way was up...or fall off a cliff. Granted, it's not that tall of a cliff, but still enough for me to be grateful to be alive and very shaken up after. I had seen other people go up seemingly fine that day and previously read reviews saying it was "fun"...NO. I should have looked closer into reviews like on AllTrails where multiple other people pointed out just how slippery that path is even when dry and the exact point where you could fall off that cliff where I almost did. I ended up slipping two more times and having to scoot up on my butt and hands because there was truly nothing to grip onto. This kind of loose dirt felt more slippery than mud, because it just completely crumbles underneath you and falls apart into nothing.

For context, I'm fit and in my 20s. I hike a lot. Have done a lot of other trails in Iceland. This was the scariest hiking experience of my life. This most dangerous part is a small section compared to the rest, but it is everything.

I really hope more people pay attention to this and pray no one faces the situation I did or worse.