Inside one of the enormous concrete tanks which used to hold thousands of gallons of processed fish oil when Djúpavík was a working herring processing plant in the 1930 and 1940s. The large rusting metal spiral under the water was a giant heating element, which was used to keep the oil from setting in the cold winter months.
The concrete is slowly decaying but each of the tanks are still accessible through small porthole-like entrances (formerly outflows for the herring oil) and are often used as visual arts and performance spaces.
[This is one of the panoramas from my June 2013 trip to Iceland. You can explore the other views of this incredible country here. https://www.360cities.net/sets/iceland-june-2013 ]