Found a golden key - where to use it?

[GeileSockeAltF4]

I found a golden key (in german it's called "heavy key", but for i cant find where to use a heavy key on the web, i think it's translated different in english).

Can somebody tell me where i can use the key? The keys description is that it will open a heavy lock and that the owner of the key must have been rich).

Thanks!

[bigsiegee]

I believe it is the key to the market place

[GeileSockeAltF4]

Found it, thanks!

[WhiteSeer]

I believe it translates as "The Massive Key"

check my guide...
https://youtu.be/zLQiQNsagNc