Constructed throughout the 1860s, the Megatron is a culvert upon which Sheffield Station—formally known as Midland Station—was built. Allowing an increase in transport to the burgeoning industrial centre, and covering the stinky sewer-filled waters, the culvert was an important architectural work that has long been forgotten.

Today, visitors to the train station stand just feet above the Victorian tunnel network, but urban explorers and guided tours can take curious patrons down into the underground. A quick hop down into the River Porter — named for its dark color — leads into the tunnels. Guides take visitors through the brick tunnels, under bridges, and ultimately arrive at the main attraction: a high-ceilinged atrium where several murders were allegedly once committed hundreds of years ago.