Teesside Park is a retail superstore and leisure development in Thornaby-on-Tees, built in 1988. Located just off the A66 near the A66/A19 interchange, it is split between the unity authorities of Stockton-on-Tees (retail park) and Middlesbrough (leisure park) with the line of the Old River Tees, which runs down the middle of the development, forming the boundary between the two authorities.