File Description: To the south-east of the White Horse, on top of Cherhill Down is the Lansdowne Monument. Erected in 1845 by the 3rd Marquis of Lansdowne to commemorate his ancestor Sir William Petty. It towers 125 feet (38 metres) above the hill and can also be seen 30 miles (48 Km) away. The hill now belongs to the National Trust. It is said that this is the highest point between London and Bristol. Lat 51 26' Lon 1 54'.