We ended our trip in Iceland with a few nights at the Ion Adventure Hotel, a boutique design hotel. It's about an hour away from Rejkyavik and is known to get amazing views of the Northern Lights since it's in the middle of nowhere. The hotel has about 30 rooms so it was intimate and quiet with amazing customer service. It's also located next to a geothermal power plant so there is a geothermal river that we snuck down to in our hotel robes for a dip. It was one of my favorite experiences because finally it was just us a random hot river - no other tourists and no lines.
We also got massages, admired the beautiful view, and got a faint glimpse of the Aurora Borealis at about two in the morning (which we watched on the hotel deck with a certain Breaking Bad actor that was also staying at the hotel). The Ion was the perfect way to end the trip and we couldn't have been more pleased with our experience!