The Blackwall Tunnel is a road tunnel located in London, England, that runs beneath the River Thames. It connects the areas of Blackwall in the east and Greenwich in the west, facilitating traffic flow across the river. The tunnel was officially opened in 1897 and has since undergone various upgrades to accommodate modern vehicles. The tunnel consists of two separate tubes, each allowing one-way traffic. It is an essential part of the A102 road and plays a crucial role in reducing congestion in the surrounding areas. The Blackwall Tunnel is particularly important for commuters and freight transport in London.