Fensham Reserve is a 48-hectare native bush reserve near Carterton in the Wairarapa, managed with Forest and Bird. It holds a remnant kahikatea swamp forest, a wetland that is home to the nationally vulnerable mudfish, and podocarps thought to be 400 to 700 years old. About 19 hectares of regenerating forest sits above the primary forest.
The reserve has one circuit track that takes about an hour to walk, with links to the old fence track and the brow track. Birds recorded there include the NZ kingfisher, tui, NZ pigeon, morepork, North Island fantail, grey warbler and wax-eye. There are two entrances, one off Cobden Road onto the main circuit and one off Upper Belvedere Road that leads to the picnic area. Parking is available at both entrances. The reserve is open to the public all the time, but no pets are allowed because of regular pest control. Belvedere and Cobham Roads are the main access roads, about 3 km west of Carterton.