Most Unexpectedly Convenient
Credit: Martin Moos / Getty Images

Iceland's Blue Lagoon has been featured in countless travel magazine photo spreads since it pooled up after the Hitaveita Suðurnesja geothermal power plant began operations in 1976. The popular attraction is still fed through the plant, which helps bring down temperatures that tend towards scalding as water is pushed to the surfaces past a lava flow (one of many) located beneath the tranquil pool. The site, which owes its beautiful color to particles of silica mud in the water, was initially popular among sufferers of psoriasis, who found that the mud helped them fight their condition, but it has become one of the island nation's defining destinations. Fortunately for Americans making their way to Europe, the hot springs are a half-hour drive from the airport and IcelandAir encourages extended stopovers. If you plan to spend some time in Reykjavik, have a soak before heading into town. If you're just on your way to London, take one the airport shuttles, have a soak, and make your connection. It's the ultimate departure lounge.