The monument was designed by John and Benjamin Green and built by Thomas Pratt of Bishopwearmouth using local gritstone at a cost of around £6000; the money was raised by subscription. On 28 August 1844, while it was partially complete, its foundation stone was laid by Thomas Dundas, 2nd Earl of Zetland in a Masonic ceremony which drew tens of thousands of spectators. Based on the Temple of Hephaestus in Athens, it is a tetrastyle temple of the Doric order, with eighteen columns—seven along its longer sides and four along its shorter ones—and no roof or cella (inner chamber).