The Trinnacle is a three-pronged gritstone pillar, high above Dove Stone reservoir, that has become a popular location for "selfies" due to coverage on social media.
You have to ford the stream and do a bit of scrambling to reach the main waterfall. The path is narrow, with a steep fall down to the stream. Be warned!
Just next to the path and a lovely spot for a picnic, these waterfalls in Greenfield Brook flow into Greenfield Reservoir, the top of the chain of 3 reservoirs.