Why is it called blackwall tunnal?

The Blackwall Tunnel is named after the nearby Blackwall area in East London. The name "Blackwall" itself is believed to derive from the black walls of a medieval fortification that once stood in the area. The tunnel, which opened in 1897, was constructed to facilitate road traffic beneath the River Thames, connecting the boroughs of Greenwich and Tower Hamlets. Its significant role in improving transportation in London further solidified its name in the city's infrastructure.