The coronation church of English and British monarchs since 1066, and a working church that manages to be both a major tourist attraction and a place of genuine religious life. Poets' Corner in the south transept has memorials to Chaucer, Shakespeare, Dickens, Hardy, and dozens more; the Grave of the Unknown Warrior near the west door is unexpectedly moving. It's not cheap, but the building and its history justify the ticket.
Westminster Abbey
Coronation church of British monarchs since 1066
A story
The Coronation Chair in the Abbey has been used at almost every coronation since 1308. It was originally built to enclose the Stone of Destiny, seized from Scotland by Edward I — the Stone was finally returned to Scotland in 1996, but comes back to Westminster for coronations.