Broneirion is a Victorian house and grounds on the hillside across the River Severn from the village of Llandinam. It was built by Welsh industrialist David Davies. It has been used as a training centre for Girl Guides since 1946 and has been owned by Girlguiding Cymru since 1992.
The house is built in the italianate style and is set in four and a half acres. The roof is Welsh slate. In November 1996, Broneirion House, Coach House, and the Lodge all became Grade II listed buildings. The bridge from the main road towards Broneirion was the first iron bridge constructed in Montgomeryshire, designed by Thomas Penson and built by Davies. It spans 90 feet (27.5 metres).
The Davies family moved into the house in 1864.
David Davies and his son, Edward, both died in 1944. Edward's widow, Lady Davies, was a supporter of Guiding. Her friend, Heather Kay was enthusiastic for a training centre for Welsh Guides, so Lady Davies offered Broneirion for this purpose.
Broneirion became the Welsh Training Centre for the Girl Guide Association in 1946 and was opened by the World Chief Guide, Olave Baden-Powell, in 1947. In 1992 it became the property of Girlguiding Cymru after a campaign that raised £510000 for the purchase and an endowment fund. At the same time, a much-needed campsite was purchased close to the house and named Cae Gwenllian. In 1995, the opportunity unexpectedly arose to buy Broneirion Lodge, on the property boundary. Both the house and grounds are used for training and camping activities, and the site is used by Guides, other organisations and private groups. The Brownie house, originally the Davies children's summer house is now a Pack Holiday facility.
Broneirion's campsite, Cae Gwenllian, was purchased in 1994. It is named after Girlguiding Cymru's much loved Treasurer and a former Chief Commissioner, Hon. Gwenllian Philipps. It has a toilet block and equipment store.