The materials used to build a bridge can vary depending on the type of bridge and the location, but some common materials include steel, concrete, wood, and stone. Steel is often used for the superstructure and supports of a bridge, while concrete is commonly used for the bridge deck and abutments. Wood may be used for smaller bridges or pedestrian bridges, while stone is often used for historic or decorative bridges. Other materials such as composite materials, aluminum, and even glass are also used in modern bridge construction.