The church building has many symbolic meanings; perhaps the oldest and most prominent is the concept that the Church is the Ark (as in Noah's) in which the world is saved from the flood of temptations; therefore, most Eastern Orthodox Churches are rectangular in design. Another popular configuration, especially for churches with large choirs is cruciform or cross-shaped. Architectural patterns vary in shape and complexity, with chapels sometimes added around the main church, or triple altars; but in general, the symbolic layout of the church remains the same.