This classic, popular route in the central Pyrénées will take you to the Portillon de Benasque (2444m), which marks the border between France and Spain, and then up the Pic de Sauvegarde (2738m).
I started at l'Hospice de France (1385m), S of Bagnères de Luchon. Plenty of space to park there, but a late start meant the parking was full at this time of the year (2nd August), so I had to drive back down and park alongside the road, next to a nice waterfall called "la Cascade du Parisien". The GPS would not locate me before I had walked back to the parking near l'Hospice de France, so I started recording from there.

I had been looking forward to having this walk and the weather conditions were perfect, a bit warm at the beginning, but then a wee breeze and the cooler temperature due to the gain of height enabled me to fully enjoy the hike.  The unmarked trail which leads to the Refuge de Venasque is very popular and I met a lot of people who were on their way down. Much less traffic after the refuge. The going is easy and never too steep, on a well-defined and rather well-maintained trail which zigzags uphill to reach the Refuge de Venasque at around 2240m (allow 2h30 for this part). Great views over the beautiful "Boums du Port" (lakes) and the steep cliffs of the Pic de Sauvegarde to the SW.

Stick to the main/upper trail (to the left) and follow it for a mere 30 min to reach the Port de Venasque (Portillon de Benasque in Catalan, 2444m), a narrow gap carved in the rock, which is not visible until you are almost there (the ascent gets a bit steeper on the last part).

Once there, some stunning views appear to the S, mainly including le Massif de la Maladeta which hosts the Pyrénées' highest peak, the Pico de Aneto (3404m). This was actually a special moment for me, as I realised it was the first time I was crossing the Spanish border during a hike !! From the Port de Venasque, I followed the trail down on the Spanish side for a few meters before veering right (WNW) on a rather well-defined trail which will take you up to the Pic de Sauvegarde. The trail disappears from time to time, leaving place to bare rock, but you will get back on it easily (it must be another story under poor weather conditions/low visibility though). At one point, you may have to use a handrail -or your hands, as I did- to descend a few meters and up again to contour a small crag, but nothing too difficult nor vertical. Allow 45 min to 1h for this part, as it is steeper and a bit more demanding -and interesting !!- from the rest of the climb. 

The views get more extensive as you get higher, with the rather impressive Pic de la Mine (Tuc dera Mina, 2708m) to the E, and la Maladeta to the S. The top of the Pic de Sauvegarde (2738m) offers a breathtaking 360° panorama, adding mainly the fantastic +3000m ridge that marks the border to the W, including the Pic de Perdiguère (3222m), to the already stunning scenery. Note that the summit area is surrounded by sheer cliffs, still it is possible to walk a few tens of meters to the W to enjoy some more stunning views over le Lac de la Montagnette, and a few meters to the N to look down at the Refuge de Venasque and admire the four lakes visited on the way up. No safe way down on the other sides it seems, so best is to retrace one's steps to the Port de Venasque and down the same way, unless you have planned a few days' trip on the Spanish side.

The data above are slightly different from what my GPS really recorded and therefore not totally reliable. Length is probably about 17km, with some 1400m total ascent and descent, and it took me about 6h30 to complete the whole walk (4h ascent, 0h30 at the summit and 2h descent).