Keret House

Keret House is a structure and art installation in Warsaw, Poland. It was designed by the architect Jakub Szczęsny through the architecture firm Centrala, and has been described as the narrowest house in the world, measuring 92 centimetres at its thinnest point and 152 centimetres at its widest. The two-story art installation was named after Israeli writer and filmmaker Etgar Keret, who was the building's first tenant.

Source: Wikipedia