Vaiatoa is the larger of the two brackish lagoons in the centre of Nanumanga, occupying much of the northern half of the island. Four small wooded islets sit inside it, and the shoreline is ringed by about 20 hectares of mangrove forest — one of the few sizable mangrove stands in northern Tuvalu.
Locals fish for milkfish and tilapia in the lagoon and harvest pandanus and breadfruit from the surrounding ground. Walking around it takes a couple of hours along a soft path that runs through coconut groves. The mangroves are best visited at high tide, when shallow draft canoes can be paddled in among the roots.