Covered bridges are wooden structures designed to protect the bridge's deck and supporting elements from weather conditions. They often feature a roof and walls, which help to extend the lifespan of the bridge by shielding it from rain, snow, and sunlight. These bridges are commonly found in rural areas and are known for their charming, picturesque appearance. Many covered bridges were built in the 19th century, showcasing unique architectural styles and craftsmanship. They often serve as historical landmarks and are popular tourist attractions. Some famous examples include the Old North Bridge in Concord, Massachusetts and the Hartford Covered Bridge in Vermont.