A 10-minute walk southeast from Cat Ba Town, the three Cat Co Cove beaches boast the nearest sand to town, though all are being developed with hotel construction. Cat Co 3 is the closest, with a small and popular sliver of sand. From there a walking trail, cut into the cliff and offering gorgeous sea views, winds its way to Cat Co 1, dominated by a new resort, then onwards to the pretty white-sand swathe of Cat Co 2.
You can also follow the road uphill straight to Cat Co 1 and 2, or take the tourist 'train' (basically an oversized golf cart; 10,000d) that trundles over the hill during the summer months.
Kayaks and jet skis are available to rent at Cat Co 1. Note that the beaches get packed on summer weekends.