The Bartolomeu Dias museum complex was officially opened on 3 February 1989, however the Mossel Bay museum industry can be traced back to the 1960’s when the Mossel Bay museum was first opened. The museum later became known as the Post Tree museum complex before being renamed again in 1989.

The Dias Museum Complex is situated near the beach, shops, restaurants, banks and the tourist information center. Inside the Maritime Museum is a shop where postcards, stamps, books, souvenirs and small gifts can be bought. On the grounds of the Dias Museum Complex are mountain tortoises, ducks and museum cat. In the Granary there are conference facilities available for 48 people or if used in cinema style, seating for up to 100 people. Catering can be arranged. Mail from the shoe is collected twice a day (once a day out of season) by the Post Office. Whales can be observed from the museum grounds during June to November.