Ibón de Salterillo & Forau d'Aiguallut
✓ Verified against the agency · AEMETA standalone half-day loop for those not summiting: La Besurta up to Refugio de la Renclusa and the Collado de la Renclusa, past Ibón de Salterillo, then down to the Forau d'Aiguallut — the sinkhole where the Aigualluts stream vanishes underground and resurfaces in France as the Garonne — before looping back to La Besurta.
Safety classification
Summer, roughly late June to September in snow-free conditions. La Besurta is closed to private cars in summer — shuttle bus from El Vado, or +9 km / ~3 h on foot each way. Not safe: with snow cover the leg above Plan de Aiguallut becomes ice-axe-and-crampon terrain per the agency's Aneto fiches, and cairns disappear; avoid storm and fog days — no shelter above the plain.
- ▲Above Plan de Aiguallut the route leaves the waymarked GR 11.5: cairned moraine and granite-slab terrain on the flank of a MIDE-5 corridor
- ▲Early- and late-season snowfields around the Salterillo basin (2,460 m)
- ▲Afternoon storms with no shelter above the Aiguallut plain
- ▲Loose livestock on the Forau/Plan de Aiguallut section (agency warning, especially with dogs)
- ▲Do not continue past the ibón toward the glacier without full alpine equipment and experience — that is the Aneto summit route
Marked official:false because the agency recognizes no lake-hike of this name: it documents (a) the easy Forau/Plan de Aiguallut walk (MIDE 1/1/2/2) and (b) the Salterillo line only as the approach leg of the Aneto mountaineering route (full-route MIDE 5/4/4/4). This classification is composed from those two fetched fiches with the turnaround at the ibón (2,460 m; ~5 h and ~600 m round trip from La Besurta). The two halves are very different: families stop at the Forau; the leg to the lake is unmarked high-mountain terrain. The lake basin has been reported dry in recent summers.