Have you ever heard about this destination?
 It's in the north of Vietnam with thousands of islands. 
You can go swimming, canoeing, fishing, diving, camping and specially, kayaking.
Some of the better-known areas are to be found in the picturesque Halong Bay area though some other coastal and riverine areas also offer this gentle waterborne activity. 
It's a great way to see coastal fauna and flora and all but the smallest family members will enjoy a day out on the water in a canoe.
More at greentrail-indochina.com