Fjordenhus is a recently completed structure built on the  Vejle Fjord in Denmark only accessible by footbridge. It is the first structure fully designed by the studio of Danish-Icelandic artist Olafur Eliasson (previously), and was inspired by the harbor’s architecture. The 970,000-brick building is built several yards into the water from the shore, with the surrounding body of water acting as its moat.

Source: An Olafur Eliasson-Designed Building Only Accessible by Footbridge in a Danish Fjord