<P> The avenues in the park were all laid out by Capability Brown, paying due respect to pre-existing plantings, some of which were from the 16th century or earlier . Brown also created the park's man - made lake in 1775--80 . He discovered a seam of waterproof "blue" clay in the grounds, and was able to enlarge the original nine - acre (36,000 m2) pond to the existing 26 - acre (105,000 m2) lake . Its clever design gives the impression of a meandering river . Brown also designed the Lion Bridge at a cost of 1,000 guineas (£ 1,050) in 1778 . Originally, Coade - stone lions were used as ornamentation . After these weathered, the existing stone examples were made by local mason Herbert Gilbert in 1844 . Queen Victoria and her husband Prince Albert also planted two trees to commemorate their visit . </P> <P> As well as the annual Burghley Horse Trials, the park plays host to the "Burghley Run" for Stamford School and an annual meet for the Cambridge University Draghounds . </P> <P> Recent developments have included starting a sculpture garden around the old ice house and, in 2007, a "garden of surprises" was created using traditional ideas of water traps, shell grottos and a mirror maze, but in a 21st - century style . The Burghley House trust has commissioned contemporary artwork in the grounds from leading artists . </P> <P> The parkland and gardens of Burghley House are listed Grade II * on the Register of Historic Parks and Gardens . </P>

16th century country house home to the annual horse trials