Hike around Höfði

Lake Mývatn translates to "Midge Lake" and if you visit here in the summer there will be swarms and swarms of midges. You might want to wear something to cover your face.

From the parking area, which is located just off Road 848 past the turn off for Dimmuborgir if heading away from Reykjahlíð, the trail begins at the gate (make sure you close the gate behind you). 

This largely forested path breaks off into many paths, but they all lead to the same place.  If that makes you nervous, then stick to the obvious wide pathway, and it will lead you to an overlook of some neat lava pillars in the middle of the lake.  From this overlook, take the trail that skirts the lake and it will lead you back towards the parking area. 

Just before the parking area when you can see the gate, there is a trail that breaks off to the left up a hill (if looking towards the parking area).  Take this short trail up to a nice overlook of Lake Mývatn.