The Park Avenue Tunnel is a railway tunnel located in New York City, running beneath Park Avenue. It connects the Metro-North Railroad tracks to the Grand Central Terminal, allowing trains to access the station from the north. The tunnel is approximately 1.5 miles long and was completed in 1910. This tunnel is notable for its unique design, featuring a brick arch structure. It is primarily used for commuter trains, facilitating the daily travel of thousands of passengers. The Park Avenue Tunnel is an essential part of the city's transportation infrastructure, contributing to the efficiency of the regional rail system.