I'm not sure I've ever been to one. Plenty of churches, but I don't think any cathedrals.
Whether you're religious or not, do you have a particular reason for being so?
_________________
It is easy to go down into Hell;
Night and day, the gates of dark Death stand wide;
But to climb back again, to retrace one's steps to the upper air –
There's the rub, the task.
– Virgil, The Aeneid (Book VI)