A fast hike over the Fimmvörðuháls trail. The way up was a fast paced hike and the way down a comfortable jog. Was going for the 5km/h speed. The weather was mixed, rained a lot on the way up but was hot. The way down was much better, dry with a little bit of sun. Highly recommend this trail. Did it a week ago with a group too. The trail is on my timeline.