Get Inside the Colosseum is the main quest in the European Boat Ride.
If Mickey takes the normal Projector Screen inside the door he has to repair, he will have to pass the Leaning Tower of Pisa and the Eiffel Tower. An easier way to get to the Colosseum is taking the secret Windmill projector and riding the gears up to a secret entrance. The quest will be completed upon hearing Small Pete's laughter.