A causeway is a raised road or path that is built over water or wet ground. It is often constructed using earth, stone, or other materials to create a stable surface for vehicles and pedestrians. Causeways can connect islands to the mainland or provide access across marshy areas, making travel easier and more efficient. Many causeways are designed to withstand flooding and erosion, ensuring they remain safe for use. Some famous examples include the Causeway Coastal Route in Northern Ireland and the Lake Pontchartrain Causeway in Louisiana, which are both vital transportation links in their regions.