Booked tickets in the UK. Very easy via Trip Advisor. Boarding the ferry was also easy.
Once we reached the island, we entered a bus that took us on a tour of the island. The bus was full and quite cramped. There were both English and French speaking on the same bus, so 2 guides were commentating. Not an issue, but had it been just one language, we may have got round a bit quicker as we had to wait at the various stops for both to finish.
There was a 10 minute break at a very limited cafe but it did sell drinks and a cake.
Depending on what side the bus you were on, depended which landmark you were able to see.
Once the bus tour finished, we were met by an ex political inmate who gave us a tour of the prison itself and a little speech at the end about his experience. This also felt rushed as we didn't have time to look at the exhibition.
We then quickly had to leave for the ferry back.
Good tour, the guides were very knowledgeable and would recommend just because of the history.
However, it was rushed, crowded, saw only half the landmarks and no time to browse the gift shop.