The Blue Lagoon was definitely my favorite part of Iceland. Here are a few things you should know before you go:

1. Make sure you pre-book your tickets so that you can secure a spot. The tickets as of January 2018 were $70 USD. This was for the comfort package, which is the most basic/cheapest one and pretty much just includes entry to the lagoon. However, I just checked their site and for August, it’s only $52 USD which includes a towel and a drink. August is probably an off-season for them so it’s cheaper. There are various other packages you can get such as access to the spa, or a bathrobe. The ticket prices also vary by time slots. Ours was 9 am, but we saw later times that were more expensive. You have to enter when your time slot begins, but you can stay until the lagoon closes.
2. They give you a bracelet which doubles as a tab. If you want to buy drinks at the bar, they scan your bracelet. After you shower and before you are allowed to exit the premises, you just pay for the total charges.

   

3. They have a free mud mask bar. So if you want to opt for the package that doesn’t include the fancy mud mask, the free one is still a nice option. Just beware – it feels freezing on your face and once it dries, your face will feel like stone. I didn’t really see any difference in my skin afterwards.

   

4. The water temperature is 99-104 degrees Fahrenheit. So even if you go in the freezing winter, like I did, you won’t feel the cold since you’ll be in the water – at least not from the neck down.

   

5. You have to shower before you get into the lagoon for hygienic reasons. You can use the showers afterwards too. They have soap/shampoo/conditioner, and blow dryers. 
6. The water in the lagoon will dry out your hair and make it feel brittle. Good thing you can use all the conditioner you want in their showers. It took a few days for my hair to get back to normal.
7. They have free lockers available, so you can store all of your stuff there while you’re in the lagoon. There’s also storage for luggage, but that’s a whole separate ordeal, and you’ll have to pay extra. 
8. Food is expensive there (as it is everywhere in Iceland, but even more so here), so be sure to pack a lunch. We made some good ol’ fashioned PB&J sammies and ate them after the shower.
9. The Blue Lagoon is manmade. It’s not heated by the earth, but rather a nearby geothermal plant. In fact, it started in 1976 when people started swimming in the waste water from the plant. Supposedly, the water had healing powers for the skin and that’s how the Blue Lagoon got its start.
10. The water is rich in minerals like silica and sulfur and is supposed to be good for your skin. However, my already dry/sensitive skin felt even dryer after a visit to the Blue Lagoon. But then again, it could also have been the soap from their showers that I used.
11. The Blue Lagoon is on the way to the Keflavik Airport – 15 minutes to be exact, versus the 45 minutes from the lagoon to Reykjavik. Since you’ll likely stay Downtown/towards the city center, the most efficient use of your time would be to go on the way to or from the airport. We went on the day we were flying back to NYC but made sure to book the early slot so that we’d have plenty of time to relax and get ready for our flight.