How to make a structure require a gold mine?

[stan0033]

Hi, I want to make a structure unit be able to be placed only on gold mines. I looked through the fields of the Haunted gold mine, but can't figuire out what makes it require gold mine for placement. Any help?

 

[HerlySQR]

I think is the field "Can be built on top" or something like that, because my game is in Spanish, so I don't how is exactly in English.

 

[stan0033]

Ah yes, I didn't see that.