Unidentified Medal

Get a good magnifier and look at the "cartouche"... the rectangle under the horses hooves; not the fence, but to the right of the last to right fence post.

I tried to blow up your picture and couldn't be sure, but it may have a purity/weight marking there... otherwise it seems an odd out of place bit.

Does it say anything... if so, what?

>>>edit>>> Your image appears to indeed have markings in that cartouche... the last letter appears to be a small case "g". I would assume it to be a gold puriy/weight mark... possibly a commemmorative token with the same specs as the more common 20 Franc Swiss gold Helvetia?

Welcome Adrian.

Thank you all, my friends.
Chrisild. Indeed, it cannot be gold because, the seller from the link you gave me, sells a medal like mine with 35 Eur. I think is silver, at this price.
Moreover, I found out the year when it was minted (1987).