In reply to simonsnake77:
It's going to be HOT in Coll de Nargo in summer. People are most likely to be climbing at Perles (sector Roc d'en Sola) because it goes into the shade at 4pm and then you can climb at 9pm. It's a 10 minute drive from Coll de Nargo, plus 10 min walk-in. You could also try Figols before 11am for shade - that's a 30 min drive, 30 min walk from Coll de N. And of course Tresponts holds shade (15 min drive north of Coll de N, 5 min walk-in) but the climbing tends to be grade 7 upwards.
The comprehensive climbing guidebook for that area is "Roques, Parets i Agulles de'l'Alt Urgell". (Coll de Nargo is in an equivalent of a county called Alt Urgell.) There are some nice multi-pitch routes in the area too.
If you need a guide I have a friend in Andorra who would do it - mountain guide, 8a climber, great English. Marco Mijares.
There is no whitewater in the Alt Urgell, you need to drive into the next valley west, at the town of Sort and further north at Llavorsi you will find lots of white water operators. There is also great canyoning in the Sort valley, and a fun canyon at Boixols, which is in the upland west of Coll de Nargo. That's a good choice in extreme heat. Lots of guides running those sort of trips.
If the heat is too much, there is reasonable climbing in Andorra and at least it's a bit higher. There are a few multi-pitch routes that are fun. The Andorra guidebook is called Roc Andorra.
I live in Andorra and climb around Coll de Nargo regularly - we were climbing at Perles yesterday, in t-shirts! If you have more questions, message me.