It’s a pretty cool place and most people seem to have it on their wish list before they even arrive in Iceland. It gets very busy at times and I’m afraid there’s no getting away from how expensive everything is (even by Icelandic standardS), but it’s a pretty magical experience on balance.
It’s very close to the airport, so a lot of people visit on their way to/from the airport. You can rent towels, dressing gowns, swimming costumes and so on, but they will all add to the entry fee. There are also various spa treatments you can book too.
My advice if you really want to go all out and go for it is to stay in one of the hotels – Silica and The Retreat, but be warned, they are very expensive indeed. You can also pay for a 4-hour visit the super luxurious spa in The Retreat without having to be a guest there.
There is a Cafe in the Blue Lagoon, as well as a very nice restaurant called Lava that is cut out of the volcanic rock and does lovely food. The Retreat also has an amazing restaurant called Moss that we visited last time we were there. I’m sure that they are aiming for Michelin stars and I think they will get there pretty quickly based on what we ate and the service.
If you want to save the pennies or fancy something different to eat, I highly recommend driving up the road to Grindavík where there are some really great places to eat such as Bryggjan, hjá höllu, Fish House and Salthúsið. You can also visit the shipwreck graveyard and lighthouse at Hópsnesviti while you’re there too.
Oh, and see that big volcano with the radio towers behind the Lagoon? It’s called Mt Thorbjorn and you can walk up to the top for some spectacular views of the whole area, including the Lagoon and Svartsengi Geothermal Power Plant (where all the water in the lagoon comes from), south to Grindavík and north to Reykjanesbær and Vogar. There are also the remains of an abandoned US Army Base WWII Radar Station in the crater at the top too.