Silfra is a flooded crack between the North American and Eurasian tectonic plates, filled with glacial water filtered to one-hundred-metre visibility. In a drysuit (provided, with full briefing) you float weightless down an electric-blue canyon, technically touching two continents at once. The water is 2°C; the adrenaline handles it. No diving qualification needed — only the nerve to slide in.
Featured in Ten adventures you can do without any training · Adventure