The mansion, abandoned due to rising costs, was demolished in 1972, allowing Wallingford Castle to be declared a scheduled monument as well as a Grade I listed building. The castle grounds, including the remains of St Nicholas College, two sections of castle wall and the motte hill, are now open to the public. An archaeological research project run by Leicester University conducted a sequence of excavations between 2002 and 2010, aiming to better understand the historical transition from the Anglo-Saxon town of Wallingford and the "burgh", to the period of the Norman castle.