Natural Hot Springs
There are hundreds of boiling, geothermic reservoirs scattered the island that are suitable for swimming. These hot springs—many of them hidden—have become places of pilgrimage for travelers. The largest cluster of naturally occurring hot springs is located in the Westfjords, which can be quite the trek for most travelers. Try the clandestine hot pool at Seljavallalaug, in South Iceland, a 12-minute walk from Edinborg. You'll quickly stumble across the huge pool, which offers basic changing facilities. Iceland's natural hot springs are especially popular in the winter months, when you can bathe with the Northern Lights flickering overhead.