The kids will get a kick out of watching the boats go back and forth from Gulangyu Ferry Pier. For a bit of family fun, why not buy some tickets and venture somewhere interesting?
When you've finished exploring this Siming District ferry passenger terminal, why not make your way to Wanshi Botanical Garden, Xiamen University, and Nanputuo Temple? They're not very far from Gulangyu Ferry Pier and also a hit with many tourists.