There are many flights to Porto Seguro, Brazil (Airport Code = BPS). From a large amount of airlines and worldwide destinations.
Below are just a few places where you can get good deals on international flights to Porto Seguro, Bahia, Brazil:
Once in Porto Seguro international airport, there will be many ground transportation alternatives to Trancoso. From air-conditioned taxi cabs to vans and buses. All must take the ferry to Arraial D’Ajuda, and then go 24 km South towards Trancoso in dirt and asphalt roads.
If you are already in Brazil, there are bus routes to Porto Seguro from many Brazilian cities. I am a frequent traveler of these 2 companies (websites in Portuguese):