By air. Cadjehoun Airport in Cotonou is Benin's only international airport. There are direct flights from Paris (Air France, with connections from across Europe), Brussels (Brussels Airlines), and several West African capitals including Abidjan, Dakar, Lomé, Lagos, and Accra. Ethiopian Airlines connects Cotonou to Addis Ababa and from there to the rest of Africa and beyond. From North America, routing through Paris or Addis Ababa is usually the best option.
From neighboring countries. Benin shares borders with Togo, Burkina Faso, Niger, and Nigeria, and all have functioning land crossings. The busiest route is from Lomé (Togo) to Cotonou -- about two hours by bush taxi, crossing at Hilacondji. From Lagos (Nigeria), the Sémé-Kraké border crossing leads to Cotonou in three to five hours depending on border queues, which can be substantial. From Burkina Faso, the main crossing is at Porga in the north, useful if you are heading to or from Pendjari National Park. The Niger border crossing at Malanville in the far north connects to Niamey.
Visas. Most nationalities need a visa. Benin introduced an e-visa system that allows you to apply online before arrival. Processing typically takes 48 hours and the visa is valid for 30 to 90 days depending on the type. Some nationalities can obtain a visa on arrival at the airport, but the e-visa is more reliable and avoids potential delays. ECOWAS citizens do not need a visa.