A lonely guy on a boat floats on the blue surface with jellyfishA lonely guy on a boat floats on the blue surface with jellyfish
Reflection of landscape architecture in the water surfaceReflection of landscape architecture in the water surface
A footprint in the form of droplets on a gray surfaceA footprint in the form of droplets on a gray surface
В математике: граница, отделяющая геометрическое тело от внешнего пространства. Наружная сторона чего-н..