Introduction to Building 4: Building No. 4 was demolished after the Provisional Government of the Republic of Korea returned to the country. It was restored to its original state during restoration. Building No. 4 consists of two floors with four rooms each. The first floor is the guesthouse for foreign guests and the chairman's secretary's office. The second floor is the executive office and dormitory of independence activists Yoo Dong-seo, Cha Li-seok, Choi Dong-ao, and Yoon Ji-seop. There is an air-raid shelter behind the building to protect against Japanese bombings. Now the demolished hole has been restored to its original state.