When you visit the area around Pic Carlit & Lac du Bouilloses you need to take someone with you - there is too much beauty there for one person alone to absorb.
A multitude of mountain lakes (16+), spread over over a large area, with the ability to camp nearly anywhere between 7pm - 9am. Swimming in the lakes are prohibited though.
Summiting Pic Carlit (2921m) is also a popular destination.
As a sidenote, there are also ~25 lakes in the Pic Péric area.
If you take all of the lakes in the Catalan Pyrenees National Park as well the few just north of the park, then there must be well in excess of 50 lakes.
One can spend a couple of days just hiking and overnighting and not see them all.