Visas here require an application filled out in triplicate: three photos and three letters (one letter of employment, one letter of reference and one letter of invitation). An itinerary, proof of financial support and a yellow fever vaccination are also required. In most cases, travelers will also need a multi-entry pass, which can cost upwards of $300. On the way out, travelers are obligated to pay a departure fee called the Redevance de Développement des Infrastructures Aéroportuaires. Without paying this and receiving the accompanying Go Pass, you will not be allowed to board a returning flight.