Several boats run day trips to nearby monkey island either in isolation or as part of a larger tour. The island apparently has monkeys, but only a few around the accomodation were in evidence. Be aware that these animals are used to getting their food from either the guests or the bins, and therefore are not afraid of humans, so they might cause a problem.
There is some accomodation on the island, that is Monkey Island Resort which consists of eight small bungalows and 20 spacious deluxe bungalows, but cosy, bamboo huts just behind a secluded beach. The food was nice, the drinks cheap, and the scenery was spectacular. There's some kayaking available, and a trail for hiking to the top of the mountain where you can take so beautiful picture of Lan Ha Bay. Nearby is the public beach, destination of lot Cat Ba island trips. It is probably the most beautiful junkyard in region.