The Republic of the Congo shares a land boundary with the Angolan enclave of Cabinda. It begins at the Atlantic Ocean and continues first in a northeasterly and then in a southeasterly direction for 250 kilometers to the tripoint with the Democratic Republic of the Congo. The boundary mostly follows the drainage divides of various central African river systems and was initially established in 1886 by French and Portuguese colonial powers. After demarcation exercises were carried out, the boundary was better defined in 1901. Modern-day Republic of the Congo and Angola agreed to redemarcation efforts in 2013, and this process is ongoing.