The Plaine du Cul-de-Sac (Plain of the Cul-de-Sac) is a fertile lowland plain, situated between Port-au-Prince and the lake of Étang Saumâtre on the border with the Dominican Republic. There are several interesting sights in the area.

The town of Croix-des-Bouquets is an interesting market town east of Port-au-Prince. Not far northeast from Croix des Bouquets is large marshy lake of Trou Caïman, known as Eau Gallée to the locals. It is the best place in Haiti to see birds and it features a colony of greater flamingos, as well as several species of heron, rare ibises and ducks.

Southeast of there is the Étang Saumâtre, Haiti's largest salt lake. It supports more than 100 species of waterfowl, as well as American crocodiles. Farther south is the Parc National Forêt de Pines, which includes the largest remaining tract of pine forest in Haiti.