Two barrel vaults intersect in architecture to form a groin vault (also known as a groined vault, double barrel vault, or cross vault). This occurs when two barrel vaults cross at right angles, creating a distinctive edge called the "groin" where the vaults meet. The groin vault efficiently distributes structural thrust to its four corners, allowing for thinner walls and more open interior spaces compared to a single barrel vault. This architectural feature was first used by the Romans and later became prominent in Romanesque and Gothic architecture
