Greenwich Park is a former hunting park in Greenwich and one of the largest single green spaces in south east London. One of the Royal Parks of London, and the first to be enclosed (in 1433), it covers 74 hectares (180 acres), and is part of the Greenwich World Heritage Site. It commands fine views over the River Thames, Isle of Dogs and the City of London.

Greenwich Park is the site of several places of historical interest and great visual appeal. A Royal park since its acquisition by a former Duke of Gloucester in the early 1400s, it was originally the site of Greenwich palace and one of the principal Royal residences of the Tudor era. Henry VIII was born here in During its time the palace was substantially altered and extended, and essentially became two palaces in one. The Woolwich road nowadays intrudes into the area between the two parts of the palace, effectively severing the riverside section of Greenwich park from the greater part of it on the hill.

The riverside section of the palace was rebuilt by Wren as the Royal Naval Hospital in the early eighteenth century. The building still stands. It became the Royal Naval College in 1873 and the buildings are still known by this title. The navy has moved out, however, and the buildings are nowadays in the hands of a trust which leases them to the University of Greenwich and the Trinity College of Music. Parts of the building are open to the public though much of it is still undergoing restoration following the Navy's recent departure. That part of the palace on the south side of the town centre is centered on the Queen's House, built by Inigo Jones in the early seventeenth century. Substantial wings with linking colonnades were added a century later. The west wing has since been further extended. The Queen's House and its extensions fell into disuse as a royal residence and became the official residence of the ranger of Greenwich Park in about 1690, then became part of the nearby naval college in later being known as the Royal Hospital School. Vacated by this establishment in 1933, it was reborn in 1937 as the National Maritime Museum.

Nowadays part of the National Maritime Museum, the cluster of buildings on the hill were originally the Greenwich Royal Observatory. It is here that the Greenwich meridian, the line of zero longitude, is defined - specifically, it passes through the centre of the Airy Transit Circle, a telescope built for George Airy, then Astronomer Royal, in Founded by Charles II in 1675, its purpose was to fix longitude for navigation at sea and was until 1948 the official residence of the Astronomer Royal; the original building was by Wren and was occupied by John Flamsteed, who was the first holder of the post. The Greenwich Meridian was adopted as the world's prime meridian at an international conference in The line of zero longitude, it divides the Earth's eastern and western hemispheres. Time is also defined here, with time zones around the world defined as Greenwich Mean Time (local time at the prime meridian) plus or minus a set number of hours.

Atop Wren's Flamsteed building is a weathervane and signal ball. Just before 1pm every day the ball is hoisted to the top of its short mast, and then dropped at the stroke of the hour. Before the days of radio communication this signaled the precise time to shipping and the tradition is maintained. There is a similar arrangement at the old town observatory on Calton Hill, Edinburgh. Inside the Flamsteed building is the suite of rooms once used as living quarters by Flamsteed and his successors, but pride of place is given to the marine chronometers designed and constructed by John Harrison - the north country carpenter who solved the problem of determining longitude. The Observatory consists of many buildings. West of Flamsteed House is a row of buildings that housed transit telescopes, including the Airy building from where the prime meridian is defined. Further east and slightly behind is the Victorian dome that houses the 28-inch refractor, the observatory's largest instrument. Behind this main, block, reached through a small formal garden, are the south building, otherwise the New Physical Building, once deemed surplus to requirements and scheduled for demolition but fortunately preserved and now housing the planetarium. Nearby is the smaller "altazimuth" building, nowadays used as a solar observatory.

Greenwich park itself is an extensive and quiet green space and is graced by plenty of trees. An avenue leading south-southeast through the centre of the park is aligned with the central spine of the Queen's House and the Naval College. At the southern end of this avenue are the gates from which, on the third Sunday of April each year, the London Marathon - the world's largest mass participation athletics event - begins. Blackheath Common abuts the park to the south, forming a combined open space of nearly six square kilometers.

In a riverside piazza adjacent to the town centre and the naval college, two famous ships sit in specially constructed dry docks. The Cutty Sark is justly famous, having set and held speed records for tall-masted sailing ships in the latter half of the Nineteenth century. She first carried cargoes of tea from China and later was part of the wool run from Australia, during which period most of her speed records were set. After spending some time under Portuguese ownership she was purchased by a Cornish seaman in the 1920's and then passed to the Royal Naval college as a training vessel. After the second world war she was restored and installed in her present position where she has been since 1957.

Nearby is the Gypsy Moth IV, an ocean-going yacht in which Francis Chichester made the first solo circumnavigation of the world in 1966/67, at the age of 65. Upon his return Chichester received a knighthood..