To the W of the entrance of the Horcones valley (which takes you to Plaza de Mulas and the normal route to Aconcagua), a small cliff offers several ice-falls and mixed climbing routes. There are options for all styles and grades and the climbs are easily accessible from the road. Routes (and conditions) are described here
Selected climbs on the cliff
1: Zona peligrosa
(120m, WI3). This is the largest ice climb. By always going for the easiest sections, you can climb the fall without exceeding 75° (WI3) but the fall is very wide and you could also link up harder sections of up to 80-90° (but never very sustained, 10m max - WI4/4+).
2: Right hand-side couloir
. This snow couloir (up to 60°) offers a short ice-step at its base (70°). It is likely that with a lot of snow, the step cannot be seen. The couloir is a good alternative to get down the main ice-fall (#1) but beware of avalanche hazard from the "bowl" above.
A curtain of near vertical ice (WI4+?). It seems the curtain never forms fully and it is rarely climbed.
: A snow couloir (60°) with a one-pitch ice-fall on the right. The ice-fall offers a 4-5m step of 80° ice (WI3+).
5: Chacal rebotante
(45m, WI4+). A very appealing one-pitch ice-fall with some 6-10m of 80-95° ice (WI4+).
Moderate mixed route (above a short goulotte).
Several very short ice-steps (<3m) of 80-90° ice a the base of the larger ice-fall are very good for practising with minimal equipment.
A one-pitch ice-fall (70-80°?) at the back of the rocky spur on the left of the main ice-fall (looking up). See the photos below to get an idea.
Further east, where the cliff is decidedly steeper, a hard mixed route was opened in 2008. Above the Laguna Horcones (exposed to the E), another one-pitch ice-fall offers more steep ice (WI4-5?).
Mendoza --> Uspallata --> Penitentes --> Puente del Inca --> Horcones
The routes are described in more detail here
. Do not hesitate to up-date ice conditions on the website.