A commenter suggested I download Tracks for my iPhone and seems to work great. Maps your walk and you can add details and photos to it.
Just 10 minutes drive north of Wellington you find Cornish Street in Petone, which is at the corner of Belmont Regional Park.
Entering into the park you follow the Korokoro stream for just over four kms to the Korokoro dam – the first dam constructed in New Zealand.
The trial is pretty flat – the odd slope upwards. However it is a narrow path and at times quite high up, so your overall pace is slower than other terrains.
Within a minute though you are into 100% bush, and several wooden bridges as you cross over the stream several times. There is a small dam a few hundred metres along the route, but the big dam is a fair hike. The signs say 90 minutes each way, but we took around 50 to 55 minutes in each direction.
My first time in Belmont. Will definitely return as one can not only go to the dam, but also to trig stations or do a one way trip coming out in the North.