SEATON-DELAVAL, a township in the parish of EARSDON, eastern division of CASTLE ward, county of NORTHUMBERLAND, 6 miles (N. by W.) from North Shields, containing 240 inhabitants. Here are the ruins of one of the most magnificent mansions in the north of England; it was erected from a design by Sir John Vanburgh, in 1707, by Admiral Delaval, and was destroyed by fire on January 3rd,. 1822. Near it is the site of the ancient castle of Seaton-Delaval, of which little remains, except the chapel, which is a fine specimen of Norman architecture, containing monuments of a Knight Templar and his lady, and ornamented with numerous escutcheons, banners, and pieces of ancient armour: divine service is still performed in it every Sunday. At a short distance from the chapel is a handsome mausoleum, erected by the late Lord Delaval, in memory of his son, the interior of which is fitted up as a chapel, having arched catacombs underneath for the reception of the dead.