Harringworth Welland Viaduct

Welland Viaduct, or Harringworth Viaduct, or Seaton Viaduct, crosses the valley of the River Welland between Harringworth in Northamptonshire and Seaton in Rutland, England.

The viaduct is 1.166 km (1,275 yards) long and has 82 arches, each with a 12 metre (40 feet) span. It is the longest masonry viaduct across a valley in the United Kingdom.

Built by the contractor Lucas and Aird, a total of 30 million bricks were used in the viaduct's construction. Completed during 1878, it has since become a Grade II listed building.

The Welland Viaduct is on the Oakham to Kettering Line between Corby and Manton Junction, where it joins the Leicester to Peterborough line. The line is generally used by freight trains and steam specials. In early 2009, a single daily passenger service was introduced by East Midlands Trains between Melton Mowbray and St Pancras via Corby, the first regular passenger service to operate across the viaduct since the 1960s. The viaduct is on a diversionary route for East Midlands Railway using the Midland Main Line route.