Zakomara

Zakomara (Russian and Ukrainian: Закомара; Belarusian: Закамара) is a semicircular or keeled completion of a wall (curtain wall) in early Russian church architecture.

It first appeared in Kievan Rus', reproducing the adjacent to the inner cylindrical (convex, crossed) vault. Early examples can also be found in Belarus and Ukraine. After the 12th century, the zakomara, initially influenced by Byzantine architecture, was adapted into a more uniquely Russian style and it became a distinctive feature of Russian churches before the emergence of Russian Baroque.

False zakomara, which is not repeating the inner shapes of the vault, is called the kokoshnik. Kokoshniks were only made as exterior decorative elements. They were placed on the walls, vaults, as well as the shrinking tiers at the base of the tents and reels of chapters in church buildings.