Plas Tan y Bwlch

Plas Tan y Bwlch in Gwynedd, Wales, is the Snowdonia National Park environmental studies centre, administered by the National Park Authority. It is located approximately east of the coastal town of Porthmadog, overlooking the valley of the River Dwyryd and the village of Maentwrog.
The centre provides courses about the Snowdonia National Park and the surrounding region of Wales.
History.
Plas Tan y Bwlch was built by the Oakeley family during the 19th century on the site of a first house probably built in the early 17th century. Additions designed by the Chester architect John Douglas were made to the house for W. E. Oakley in 1872. The nearby Oakeley Arms Hotel was also once part of the estate but was sold off in the early 20th century.
The Oakeley family owned a huge slate quarry in Blaenau Ffestiniog from which slates were carried to Porthmadog by the Ffestiniog Railway which passed through the estate.
Plas Tan y Bwlch is thought to be the first house in North Wales with electric lighting powered from its own hydro-electric station, which was commissioned in the 1890s. A pipeline from the nearby Llyn Mair fed water to a Pelton wheel, which was located in a small power house on the hillside immediately behind the house. It ceased to operate soon after 1928, when the public hydro-electric power station at Maentwrog began supplying the area. In June 2013 a new hydro-scheme, costing £420,000, and similarly tapping the water from Llyn Mair, was opened. The water falls to the turbine, and the scheme is expected to meet most of the Plas' electricity needs.