Follow the Whanganui River's western riverbank seawards for 8km and you'll arrive in Castlecliff, a wonderfully low-key beach 'burb dominated by a huge cat-food factory and the brilliant black-sand Castlecliff Beach. There's patrolled swimming here in summer, plus a playground, skate park and views up the coast all the way to Mt Taranaki. Let the kids roam free.