Located in the village of Sauk City at the north end of the village’s historic business district, this tiny, highly intact red brick house was built between 1850 and 1857. In 1866, Lisette and Otto Hahn Sr. purchased the house. Otto Hahn Sr. (1829-1913) was a native of Germany and a harness maker and leatherworker by trade. After emigrating to Milwaukee in 1849, he moved to Sauk City in 1852. Since Sauk City was populated mostly by other German-speaking immigrants at this date, Hahn fit in nicely and the successful pursuit of his trade enabled him to marry Lisette Nentz (1835-1871) in 1856. By 1866, Hahn needed a new shop for his business and the couple needed more room for their three (soon to be four) children, so they purchased this house on Water Street and Hahn built a now non-extant workshop next door. After Lisette Hahn died in 1871, Hahn raised their four children by himself. He lived in this 750-square-foot house until his death in 1913. Hahn's descendants owned the house until 1952, when they deeded it to the village to be used as a house museum.

The Hahn house has one principal elevation that faces west onto Water Street and another that faces east towards the Wisconsin River. From the street, the house appears to be one story tall, but there is an exposed full basement story on the downhill slope that runs form the street towards the river. Both stories contain two almost equal sized rooms: a parlor and a bedroom in the first story, and a kitchen and a dining room/bedroom in the basement. These rooms have wide board floors and plastered walls and ceilings. Wood stoves and a built-in baking oven in the basement provided heat.

The Hahn House is open seasonally for tours.