How many keys in Tibia can open more than one door?

Question

We usually think about keys being exclusive to a particular door (like the Hellgate Key) but some other keys can open more than one door in Tibia, being an extremelly valuable knowledge! A good example of it would be Key 3802. For some reason, this key opens the famous Dwarven Mine Hub AND Dwacatra prison, even though both places do not share any relation at all. Not only that, this key can open several doors in the Dwacatra entrance and also all the access of the Mine Hub!

Which examples we can cite about keys in Tibia that can open more than one door?

Answer 1

I found only a few of them :

• Key 0000 Rumours says it once opened every door in Tibia.

• Key 0909   It opens two doors on the ground floor of the Falcon Bastion.

• Key 3802  It opens the famous Dwarven Mine hub and Dwacatra prison.