Mývatn lake is right on the 1 loop road around Iceland and thus impossible to miss. Lots and lots of people come to the area for the hot spring baths (mainly via Akureyri from the looks of it) and I have to say: don't do the Blue Lagoon - come here instead! Just open TripAdvisor for the Blue Lagoon and sort by negative reviews first to read how disgusting and overpriced it is plus the scenery down there is nothing spectacular for Iceland standard, thus it's basically for those with little time or lack of venturing further than Reykjavik and the Golden Circle. But this isn't a review for the hot springs anyway.

The lake is large but I don't find anything special about it. There were some ducks but overall, boring. The interested sections were the natural baths were they filmed Game of Thrones (look it up yourself as I won't post any story info no matter how old/minor). Unfortunately just a handful of people crowd out the small entrance and tourists often hang around here longer than one would think is worth checking it out for. There are quite a few of these and you can do mini hikes. The ever changing weather in Iceland made it a no-go for anything but 10min outside the car.

Unfortunately I didn't find it too amazing (the hot spring spa was nice) and it just seems like a regular place in Iceland. Still nice, don't get me wrong, but I wouldn't rate it WH material.