Located in the main building, the museum displays Amos Anderson’s art collection and information about his personal history. The museum was opened to the public in 1965 according to the wishes of Amos Anderson. The house underwent a thorough renovation in 2018–2021 when the interiors regained their original style from the 1930s. The interior of Söderlångvik is mostly classic design featuring both antique furniture and retro-style furniture. Most of Amos Anderson’s library is located here; the rest is in Amos’ apartment in Helsinki, which was opened as the museum Amos Andersons Hem in March 2023.