One of the most curious buildings in Japan is the Gate Tower Building in Osaka, Japan. This building is the result of an unusual compromise between the land owner and the Japanese government. The 5th, 6th and 7th floors of this 16-story office building is occupied by an express highway – passing right through the building. On the building’s floor information board on the ground floor, the tenants for the three floors are listed as the Hanshin Expressway.

The tunnel does not make contact with the building. Highway passes through as a bridge-tunnel, held up by supports next to the building. The highway is surrounded by a structure to protect the building from noise and vibration. [Source]