Tours of the triforium in St Paul’s Cathedral

St Paul’s Cathedral is running occasional tours of its triforium, the space high up above the nave once again during December.
The triforium is a huge hidden corridor that runs around the nave hidden high up above the heads of the worshipers below. No one is entirely sure why the space is called a Triforium, but in ancient times someone described a similar space in Canterbury with such a name, and it stuck.
For those cathedrals that are large enough to have one, it’s a valuable space