The Lake Pontchartrain Causeway is a bridge and causeway located in Louisiana, USA. It spans approximately 24 miles over Lake Pontchartrain, connecting the cities of Metairie and Mandeville. This structure is one of the longest continuous bridges over water in the world, making it a significant engineering feat. Opened in 1956, the causeway consists of two parallel bridges, allowing for two lanes of traffic in each direction. It serves as a vital transportation link for commuters and travelers, providing access to the North Shore of Lake Pontchartrain and enhancing regional connectivity.