This is a steep hike to Falls River. It is about 10 kms round trip, (5km out-and-back), with about 350m of vertical. Plan on three hours of walking, but five to six hours including stops. (This is NOT the hike to the Falls River swing bridge you will see online and in most books/brochures.) The trail starts/intersects the Abel Tasman Coastal trail near at Torrent Bay. The trail goes steeply uphill until it meets Falls River, and follows it upstream a few hundred meters to some rock pools and small waterfalls. (Tame eels there.) After that, the official trail ends and you are "on your own". If you want to see the actual very large falls you will need to continue upstream. You have to cross the river a few times and pick your way along the sides, sometimes climbing on the rocks on the "true right side" of the river. This is NOT a safe hike, but worth it if you are comfortable with the risk. (I've never brought a saftey rope, but it could be useful depending on how slippery the rocks are that day.) After 30 to 60 minutes of upstream travel, you get to a deep swimming pool and the river turns 90 degrees to the left. You can go a bit further upstream where you can see the large water falls, and it is not possible to go any further.