The approximately 200 km frontier between Cameroon and Rio Muni, the continental part of Equatorial Guinea, extends from the mouth of theCampo or Ntem River in the Atlantic Ocean in the west to the tripoint with Gabon in the east. It was vaguely defined by French and German colonial powers in 1885 before Spain fully gained control of Equatorial Guinea. No additional colonial or modern agreements were made defining the boundary, and it should be considered de facto for its entire length. There are no known official boundary disputes between the two States, although Equatorial Guinea has been accused of possible encroachment by Cameroon in the construction of unilateral boundary works.