If you're looking for some mental stimulation, make sure you visit Musée Honmé. Whether it's history, traditions or cultural practices, you'll find lots of interesting displays to keep your mind active here.
You'll be spoiled for sightseeing choice when visiting Porto-Novo. Musée Honmé is a good place to begin here, but there are many other worthwhile places to consider. Royal Palace, Charles de Gaulle Stadium, and Da Silva Museum are not far from the collection of historical artifacts and will top off your day nicely.