A 315-hectare privately-owned wetland and important bird habitat, protected under a QEII open space covenant.

It is regarded as the largest and most important privately owned wetland in New Zealand.

The Sinclair wetlands/Te Nohoaka o Tukiauau are part of a 2000ha wetland connecting lakes Waihola and Waipori on the Taieri Plain, 40 kilometres south of Dunedin. The wetlands were named after Horace (Horrie) Sinclair, a conservationist who bought the property in 1960 and had the vision to let it revert to its natural state. Mr Sinclair was awarded an MBE for services to conservation in 1984.

Mr Sinclair gifted the wetland to a wetland volunteer group called Ducks Unlimited NZ (DUNZ) who took on the management responsibility of the area. DUNZ covenanted the wetland in 1984, ensuring long-term protection and public access to the special area.

It is now owned by Te Runanga o Ngai Tahu.

The wetland consists of ponds, water channels, swamplands, and scrub-covered islands. Over 60 species of bird live in or regularly visit the wetland.

Walking tracks and an information centre are open to the public, and accommodation facilities are also available.