The effect of a low, lonely wave on a blue water surfaceThe effect of a low, lonely wave on a blue water surface
An old brick wall illuminated by a flashlight beamAn old brick wall illuminated by a flashlight beam
Vintage wooden boards on the pages of the magazineVintage wooden boards on the pages of the magazine
В математике: граница, отделяющая геометрическое тело от внешнего пространства. Наружная сторона чего-н..