St James’s Park is the oldest of the Royal Parks; its pelicans go back to a gift from the Russian ambassador in the 17th century. Ducks, geese and swans also live on the lake, and the banks are densely planted. To the east the park opens onto Horse Guards Parade, and to the north The Mall runs to the palace. A good route between Westminster and Buckingham Palace, quieter than the streets alongside.
Background
St James's Park is a 23-hectare (57-acre) urban park in the City of Westminster, central London. A Royal Park, it is at the southernmost end of the St James's area, which was named after a once isolated medieval hospital dedicated to St James the Less, now the site of St James's Palace. The area was initially enclosed for a deer park near the Palace of Whitehall for King Henry VIII in the 1530s. It is the most easterly of a near-continuous chain of public parks that includes (moving westward) Green Park, Hyde Park, and Kensington Gardens.
It includes The Mall to the north, and is bounded by Buckingham Palace to the west, Horse Guards to the east, and Birdcage Walk to the south. It meets Green Park at Queen's Gardens with the Victoria Memorial at its centre, opposite the entrance to Buckingham Palace. St James's Palace is on the opposite side of The Mall. The closest London Underground stations are St James's Park, Green Park, Victoria, and Westminster.
The park is Grade I listed on the Register of Historic Parks and Gardens.
From Wikipedia: “St James's Park”, licence CC BY-SA 4.0