The Robben Island Museum is introducing a two-tier pricing model for international visitors and South Africans, which will see a sizable hike for tourists.
It will take effect on June 1.
The museum, tour operator said this decision was "based on an annual financial analysis".
"We believe that this decision will have a positive turnaround on our long-term financial sustainability as an organisation whilst also contributing to an increase in domestic visitors," said Blayne Crocker, chief financial officer.
Robben Island's tour promises to comprise a ferry return trip from Cape Town, transport on the Island, a guided island tour and a guided prison tour by an ex-political prisoner.
"Operationally, all of these come at an annual increased cost and has an adverse impact on revenue," the museum said in a statement.