This is at the Geothermal Area at Geysir in Iceland. This Structure was used to heat up Houses in the Area. Today about 90 % of all Houses in Iceland are heated up with Geothermal Water. It means there is one Pipeline System for hot Water and another Pipeline System for cold Water. The hot Water is both for Heating and for Personal use. It is not free but we pay way less then most other Nations for heating. One of just a few things that are not Expensive in Iceland.