Photo of Westminster Abbey in London, England.
A church was founded on the site in the 7th century. The present day abbey was designed by architect Christopher Wren and begun in 1245. It's official name is Collegiate Church of St. Peter at Westminster and is designated as a Church of England Royal Peculiar: which means it is directly responsible to the sovereign.
Since 1066 the site has been the place of coronation for all but 2 of the English/British monarchs. There have been 16 royal weddings there since 1100.