Benagil Caves Boat Tour. Our core boat trip from Portimão to Praia da Marinha and the Benagil Cave, entering most of the caves along the route conditions permitting. Every operator on the Circle is booked direct. No commission, no middleman, no booking fee stacked on top: you deal directly with the people who run it. Reserva direta com quem opera, sem comissões e sem intermediários. #algarve #algarvecircle #portugal #thingstodoalgarve #benagilcavetours