Swim In The Blue Lagoon
Ticked off in February 2013
What it is
The Blue Lagoon is a geothermal spa in a lava field, with milky-blue water at around 38°C.
How to do it
Book ahead online; it's about 20 minutes from Keflavík Airport, so many people go on the way to or from a flight.
Top tip
Check whether volcanic activity on the Reykjanes peninsula has affected opening before you go.
My experience
Ticked off, but the full story is still to be written up.