The region is known for its countryside, which includes the North Downs and the Chiltern Hills as well as two national parks: the New Forest and the South Downs. The River Thames flows through the region and its basin is known as the Thames Valley. It is also the location of a number of internationally known places of interest, such as HMS Victory in Portsmouth, Cliveden in Buckinghamshire, Thorpe Park and RHS Wisley in Surrey, Blenheim Palace in Oxfordshire, Windsor Castle in Berkshire, Leeds Castle, the White Cliffs of Dover and Canterbury Cathedral in Kent, Brighton Palace Pier, and Hammerwood Park in East Sussex, and Wakehurst Place in West Sussex. The region has many universities; the University of Oxford is ranked among the best in the world.