Scrabo Tower is a 135 feet high 19th-century lookout tower or folly that stands on Scrabo Hill near Newtownards in County Down, Northern Ireland. It provides wide views and is a landmark that can be seen from afar. It was built as a memorial to Charles Vane, 3rd Marquess of Londonderry and was originally known as the Londonderry Monument. Its architectural style is Scottish Baronial Revival.