The Fjaðrárgljúfur is a canyon in the south of Iceland. It is 100 m deep and about 2 kilometers long. It mainly became popular when Justin Bieber filmed one of his music videos there.
Where to park: Fjaðrárgljúfur can be reached over a dirt road. At the end of it is a parking spot. The road can be driven with a normal car but it is not really pleasant and it will take up to 30 minutes or longer.
What to do: hike up the Fjaðrárgljúfur. Plan in around 1 to 2 hours.
Tips: Take some time to enjoy the silence.
Personal opinion: Magical place. Spare some time, walk completely up, sit in the grass and just enjoy the view.