South America the Darién watershed along the Colombia–Panama border, although some may consider the border instead to be the Panama Canal. Geopolitically and geographically all of Panama – including the segment east of the Panama Canal in the isthmus – is typically included in North America alone and among the countries of Central America. Almost all of mainland South America sits on the South American Plate. South America is home to the world's highest uninterrupted waterfall, Angel Falls in Venezuela; the highest single drop waterfall Kaieteur Falls in Guyana; the largest river (by volume), the Amazon River; the longest mountain range, the
Waterfall Country (Wales) now part of the unitary authority of Powys. A few miles further west are Henrhyd Falls on the Nant Llech, a tributary of the Tawe and to the southwest are Melin Court Falls on the Melin Court Brook, a tributary of the River Neath. These, along with Aberdulais Falls on the Dulais, a further tributary of the Neath are also encompassed by the term 'Waterfall/s Country' by some writers. Collectively the falls are one of the most popular natural attractions in South Wales, a fact which has brought about problems of erosion in the vicinity of many of the falls.