Idea of Great Wall Icon
The middle of the icon looks like an ancient castle with three pillars on top and a passageway underneath. Behind and in front of the central piece are parallel lines that run away and to the castle portion. Behind the central image the lines zig zag whereas the lines in front are smoother and linear.
This Great Wall icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 6,200 icons, all in the same style and quality.