The Argentine Pampas

Parque Nacional Laguna Blanca
Here we did 2 day walks.
1) Cerro Mellizo Sur
Climbing this volcano we arrived at what we thought was the top, only to realise that we'd ascended the lower side of the crater. As we were thinking about going up to the proper summit a thunderstorm appeared out of nowhere and we had to leg it down as quickly as possible, being bombarded by big hailstones! (8km, 3h, 420m ascent/descent)
2) Loop of Laguna Blanca
A pleasant 7 hour walk round the lake, with good views of the distant mountains, plenty of bird life on the lake, and where the weather changed seemingly every 15mins. Sun, rain, wind, sun, storm, cloud.... (22km, 7h, 450m ascent/descent)

Parque Nacional Lihue Calel
We spent a short day walking up the highest hill in the region - Cerro de la Sociedad Cientifica Argentina (587m), (from the top of which it felt like we were on top of a small island in the middle of a huge sea of Pampa - flat in all directions as far as the eye could see), and then wandering up a small valley to see some rock art. (15km, 4h, 250m ascent/descent)