The Penshaw Monument is a familiar landmark in County Durham, England and is located on Penshaw Hill, which at a height of some five hundred feet overlooks the Wear valley. It was built in 1844 to commemorate John George Lambton, first Earl of Durham and the first Governor General of Canada.

Designed by the Newcastle architects John and Benjamin Green and built by Thomas Pratt of Sunderland, the monument is a half-sized copy of the Theseion, the Temple of Hephaestus, at Athens. Regarded as the best example of a Doric Hexastyle temple in Britain it is constructed from gritstone taken from the quarries of the Marquess of Londonderry, and stands seventy feet (twenty metres) high and is one hundred feet (thirty metres) long by fifty-three feet (sixteen metres) wide. It features eighteen Doric columns arranged in four rows of seven, each of which is six feet six inches in diameter, one of which is hollow and features a spiral staircase providing access to the upper level. The door leading to the staircase has however been kept permanently closed ever since a fifteen year old boy fell to his death from the top of the monument on the Easter Monday of 1926.

The original inscription on the monument (which has since become illegible) read;

This stone was laid by Thomas, Earl of Zetland, Grandmaster of the Free and Accepted Masons of England, assisted by the Brethren of the Provinces of Durham and Northumberland, on August 28th 1844 being the Foundation Stone of a memorial to be erected to the memory of John George, Earl of Durham, who after representing the County of Durham in Parliament for 15 years was raised to the Peerage, and subsequently held the offices of Lord Privy Seal, Ambassador-Extraordinary and Minister of the Court of Petersburg and Governor-General of Canada. He died July 28th 1840, in the 49th year of his age. This monument will be erected by the private subscriptions of his fellow countrymen, admirers of his distinguished talents and exemplary private virtues.

Originally in the ownership of the Lambton family the Penshaw Monument was given to the National Trust by the fifth Earl of Durham in 1939.