The place where the Japan-US Treaty of Peace and Amity was signed in 1854 was the former British Consulate General, which was the museum's predecessor. Inside the museum, valuable historical materials related to the opening of Japan and the opening of Yokohama's port are collected. It is said that Commodore Perry and the shogunate met under the ``Tamacampus'' tree in the courtyard, which still stands today. The mascot character ``Tanemaru'' celebrating the 150th anniversary of the opening of the port in 2009 was designed as this ``Tamagusu tree spirit.'' In the adjacent open port plaza, there is also an exhibition of Japan's oldest brick manholes and sewage pipes.
