can still be seen beside the feeder sluice. In 1815 the tub boats were discontinued and a tramway built along the Taff. There is a public picnic site by the Radyr weir. A hydro-electric scheme was built in 2016 on Radyr Weir to generate renewable energy. The Radyr Weir scheme channels more than 500 million cubic metres of water per year through two screw turbines and is expected to generate 400 kW — enough energy to power three of the city’s leisure centres — which will save 700 tonnes of CO2 annually. The River Taff through Radyr is flanked on both sides by an undeveloped greenway that passes uninterrupted through northern Cardiff all the way to Cardiff Castle in the centre of the city, before the river enters Cardiff Bay. Radyr Woods Nature Area Radyr Woods is a Site of Nature Conservation Importance and the adjoining Hermit Woods is also a Local Nature Reserve. The community nature reserve covers . It has a network of footpaths and boardwalks and includes evidence of Iron Age settlements and remains of an early cooking hearth. Originally part of the Tudor deer park owned by the Mathew family and later Radyr Quarry, the area is owned by Cardiff Council and Plymouth Estates, and managed by the Radyr community council with the support of Cardiff Council's Parks Service. Radyr Woods provides habitats for a wide range of species. It also has a number of natural springs that feed a duck pond and a kingfisher pond. Recent housing developments between the reserve and the railway line have added complementary public open space with picnic areas and a children's play area. Since 1986 all maintenance and development of the reserve has been carried out by a volunteer group known as The Friends of Radyr Woods. Radyr hawkweed Radyr hawkweed is the common name of Hieracium radyrense, a very rare endemic member of the aster, daisy, or sunflower family. It is a microspecies, so far only identified at Radyr. It was first identified in 1907 at the quarry, was described as a variety in 1948 and then as a separate species in 1955. It has rarely been seen and regular surveys between 1998 and 2004 indicate that today only a single population of about 25 plants survives in the wild. In the first survey of 1998, only nine plants were identified in one single Radyr garden, where it