Henley Lake is an artificial wetland on the eastern edge of Masterton, created in the 1980s out of farmland that flooded regularly from the Waipoua River. It is now the best bird-watching spot in town, with regular sightings of black swans, royal spoonbills, white-faced herons, and a colony of New Zealand scaup.
A 3-kilometre walking and cycling loop circles the lake, mostly flat, well graded, and exposed enough to be uncomfortable in the wind. The Henley Lake Park itself has picnic tables, BBQ areas and a children's playground. Best at dawn for birdlife, in late afternoon for the light over the Tararua Range to the west.