Cinematic 4K Timelapse. 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 sea ocean gulf inlet cove water cumulus cloud clouds green grass meadow sky simple mere plain pure sunny spring summer autumn lakes. 3840×2160 UHD 4K.