Nassau House also known as the Schlusselfelder Foundation House (Schlusselfeldersche Stiftungshaus) is a medieval residential tower, which is one of the most famous and significant sights of Nuremberg.The Nassau House is the only surviving residential tower in Nuremberg, which was not completely destroyed (but badly damaged) during World War II and which is considered one of the oldest buildings and one of the few examples of Romanesque architecture in the city.The building has a defensive character only from the point of view of symbolic and decorative significance.The Nassau House has a corner location and is built in a row with other buildings. It is made of red sandstone on the model of northern Italian residential towers. It has four floors and a gallery, which is crowned by a high roof.The two lower floors and the vaulted cellar (basement) of the tower date from the beginning of the 13th century and testify to the Romanesque architecture of Nuremberg. In 1422-1433, the upper floors were added, including an architectural bay window and a crenellated stone balustrade with a frieze of the coat of arms, octagonal corner escrera turrets and "royal" attribution. The upper part of the tower demonstrates typical elements of Gothic architecture.