I took one of the two hour tours from Paracas to the Islands and enjoyed the experience though would not feel as though I missed out on much if I hadn't done it. It was good to see the sea lions and birds from up close though I didn't feel as though there's anything particularly unique about what you see as I've done almost identical tours other places in South America.
The landscape of the islands is interesting and the guides commentary (in English, Spanish and German!) around the history of the island, in particular the farming/collection activities of the bird crap!, added to the experience.
I was definitely impressed by the organisation of the tours and the quality of the guide's presentation. This is one of the only places in my 9 months of travel around South America that I've come across guides who can speak decent English.
Overall, the Ballestas Islands are worth seeing if done in conjunction with the Paracas Reserve however I wouldn't advise anyone to go out of their way to see the solely the islands.
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