A great intro climb if you're new to El Chaltén. There are approaches from both the East and West. This description is for the western approach starting from the Torre Glacier.
The approach follows a fairly direct line up the couloir dividing Aguja De L's and Saint Exupery, gaining 450-600m in elevation over ~1200m. During warm weather in January, the route was mainly 4th class scrambling, with two ~75m, 30-35º snowfields in the upper 300m before the col. 1/3 to 1/2 of the way up you'll hit an obvious bivy (if it's your first Patagonia climb, it's probably a good idea to stay here the night before you summit) and then break onto relatively flat ground before continuing up the couloir. This is your best opportunity to get lost. Trending straight is probably your best option; we trended left and ended up making sketchy traverses back right to regain the line.
Once you hit the col between De L's and Saint Exupery (Col de los Austriacos), head southeast, making a short traverse across the dihedral coming up from the East and climbing up a short (20-30 m) face with a left-facing flake to gain the shoulder below De L's. Head across the shoulder towards De L's and climb four pitches (using 70m rope) up the sloping arête to the summit. The last pitch may be the crux, depending on how you decide to navigate it. The best exposure is found heading through the obvious notch to the southeast face and climbing a short 10-20m section to the summit.
Start from Polacos, near the base of the obvious right-trending couloir separating De L'S and Saint Exupery.
Standard rack to BD #3s. Anchors on summit, on route directly below the summit, and again halfway down the decent. We stretched rope on one short (~25m) and two long (~65-70m) rappels to get back to the shoulder. Another short rappel gets you to the Col, and then you have the option of a long (-70m) rap about halfway down the couloir to (potentially) speed things up.