Onlu 20 minutes drive from Keflavík international airport, Blue Lagoon Iceland Resort & Spa is a magical oasis where healing waters, luxurious accommodations, gourmet dining, and stunning views come together.

Pros: Iconic Geothermal pool experience
Cons: Overprices and often crowded
Nearest alternative: Sky Lagoon in Reykjavík (can be less busy, but it's not the same ,,blue water + mud'' kind of experience)
Similar lagoon: Earth Lagoon (previously Mývatn Nature Baths) is less ,,fancy'' and cheaper, with a similar setting (North Iceland)

Book either directly at https://www.bluelagoon.com/ or via the link included (occasionally cheaper)