Onsen - Takayama or Gero

I'm heading to Japan in just a few weeks, and will be in Takayama for a few days. For some reason, it didn't occur to me until just a couple days ago that I should try to visit an onsen while I'm there. Unfortunately, I've only been able to find a couple possible onsen online.

The one place I've found in Takayama looks more like a rather modern public bath (sento?) than a hotspring. Has anyone been here, or do you know of other onsen in Takayama?

http://www.kankou-gifu.jp/en/hotsprings/takayama.html

Gero is just a short train ride to the south, and I understand there are several onsen located within some of the ryokan, and I can buy a pass for some of those.

Does anyone know if any of the onsen in Gero are open to the public later in the evening?

Thanks!

The onsen which is recommended in a Takayama area is Shin-Hotaka Onsen and Oku Hida Onsen.
It is acceptance time of a visitor from a hotel of Gero onsen and the outside of Ryokan.
http://homepage1.nifty.com/fuufuyuuyuu/sub14/gero.htm

There is a free outdoor bath in a riverbank of onsen street of Gero onsen.

It's a few days late, but:

Arigatou gozaimashita, Nagashima-san.