Westminster Abbey is most certainly an icon of England, and has been for over 900 years.
It was established in the 1040s by King Edward the Confessor - but he died before its completion. Between the 13th to 16th centuries the Abbey was rebuilt in the Gothic architectural style. The only part of Edward's Abbey still visible are the arches in the undercroft. As part of the re-build, Henry III built a shrine to Edward the Confessor, around which are buried a cluster of Medieval Kings and Queens. In the Tudor period the Henry VII chapel was built, which has a spectacular fan-vaulted roof. Henry VII is buried there as is his grand-daughter Elizabeth I.
The stamp below is from the 900th Anniversary of Westminster Abbey issue from February 1966.