Diving between the continents

Silfra is a rift in the Earth's crust located within Þingvellir National Park, Iceland (the odd letter Þ is pronounced like a "th" so you will also see it spelled "Thingvellir"). 

This rift is actually the boundary between the North American and Eurasian tectonic plates because the island of Iceland sits smack dab atop of the Mid-Atlantic ridge where these two plates are rifting apart from each other by a few centimeters each year (which is why Iceland is seismically and volcanically active).

The rift has filled with clear, cold glacial meltwater a couple of degrees above freezing.  Sounds like a great place to go scuba diving, doesn't it?  Here's one picture of the rift from someone who dove down into it.

Looks like a lovely place for a swim, doesn't it?  Below is another picture under the water.  I found it in a list of "The World's Best Underwater Photographs 2010" and thought it was pretty cool.

Magnus Lundgren/Barcroft Media

The left wall of the rift is North America, the right wall is Europe.