Two valks on the (Hoornseplas http://www.meerschap-paterswolde.nl/), a recreational lake dug between 1971 and 1973 just at the south side of Groningen. Because the boat was given the name /Valk/ (Falcon), most boats of this type feature the typical Falcon icon on the main sail, as does this boat. Because these two boats are made from Polyester, they are also called /polyvalks/. The origal design from 1939 was made of a special type of plywood, in order to promote the material.
The smoke in the background is from the (CMS http://www.csmsuiker.nl/) factory, which turns sugar beets into sugar. When active, the factory produces a distinct smell, that can be noticed all around the city.