A beautiful popular outdoor recreational area that towers over the downtown Reykjavík. It's only 61 metres above sea level, but still has quite a presence. On top of the hill stands the landmark building Perlan, on top of six water tanks.
It's a lovely place for a picnic on a sunny day. The view is great and the area is comfy. There are various bunkers on the hill built by the US occupation force during the WWII and also glacially scoured bedrock from the last ice age close to the Nauthólsvík beach area.
Bring a towel, as you might end up in the Nauthólsvík beach if the weather is warm and the mood is right.