Wainamu Falls, also called Waitohi Falls, is a short bush walk to a small series of waterfalls, with a 5-metre cascade, set just behind Bethells Beach in the Waitākere Ranges. The walk circles Lake Wainamu, which sits among sand dunes and is warmer for swimming than the ocean. Children can slide down the dunes, so a bodyboard or skimboard is useful on the walk. Near the lower falls there are two smaller falls and a few swimming holes, which are quieter than the lake.
The walk takes about two hours as a loop. The first section follows the Waiti Stream, where feet get wet, before it reaches the lake. The falls can have little or no water in dry summers, so the site notes that a long dry spell means a weak waterfall.
The car park is on the left just after the junction of Bethells Road and Tasman View Road, marked by a sign for the Lake Wainamu Track. It has no facilities, but toilets and picnic tables are at the Bethells Beach car park, and there is a long-drop toilet near the lake. The drive from Auckland City takes about 50 minutes on sealed roads.