What are Architectural style that use round arches and blunt heavy walls?

Architectural styles that utilize round arches and blunt heavy walls include Romanesque architecture and Byzantine architecture. Romanesque architecture, prominent from the 9th to the 12th centuries, features thick walls, sturdy piers, and large towers, often with barrel vaults and round arches. Byzantine architecture, while also using arches, is characterized by its domes and intricate mosaics, reflecting a blend of Roman and Eastern influences. Both styles emphasize solidity and structural integrity, creating a sense of permanence.