Cinematic 4K. Aerial shot with drone. A lake is an area of variable size filled with water, localized in a basin, that is surrounded by land, apart from any river or other outlet that serves to feed or drain the lake. Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. Lake bay gulf inlet cove bight loch firth land area zone fly flying over mount mountain mountains valley valleys plain plains flat topography basin catchment river basin catchment area green forest woods trees wetlands wetland swamp quicksand marsh bog quagmire morass clouds flood flooding flash flood deluge inundation submersion 3840×2160 UHD 4K.