Slightly related, examples for exceptionally beautiful spiral staircases that turn anti-clockwise are the original [0] and 1930s [1] Bramante staircases in the Vatican, which feature a double-helix design. The original could be used by carriages.

[0] https://upload.wikimedia.org/wikipedia/commons/c/ca/Bramante...

[1] https://upload.wikimedia.org/wikipedia/commons/5/5b/Vatican_...