The stamp below left shows the prehistoric monument Stonehenge with images of a gyroscope and navigation by stars. It was designed by J Fisher and issued in October 1990 as part of a set to celebrate Astronomy. Stonehenge has been said to be a kind of neolithic observatory, although many other theories exist.
No-one really knows how old Stonehenge is, but it is reckoned to be between 4000 to 4500 years old. The earthworks which make up the earliest part of the site are older yet, dating from around 3100BC.
Stonehenge is a World Heritage Site, marked by the United Nations as being of outstanding cultural significance to the common heritage of mankind. This was commemorated in the stamp below right, from April 2005. The Stonehenge stamp is shown with the Wet Tropics of Queensland in Australia, another World Heritage Site.