Charles and Camilla are staying at this country house

Camilla, wearing a cream outfit with a peach-coloured wrap, sat bedside the Prince, who waved to the crowds gathered outside the main entrance.

The concert, which featured the best of Welsh music, was a strictly private event with invited guests only.

The couple are staying at the nearby Vaynor Park near Welshpool, but Mrs Parker Bowles has not accompanied the Prince on any of his official engagements.

On Friday he opened the National Botanical Garden of Wales at Llanarthne in Carmarthenshire.

In his first engagement on Saturday the Prince toured Machynlleth where pensioner John Eliss asked him to deliver some 100th birthday cards to the Queen Mother.

John Eliss handed the Prince cards for the Queen Mother

Then the Prince travelled to Caernarfon Castle, the scene of his investiture more than 30 years ago.

There he performed the official opening of the Regimental Museum of the Welsh Fusiliers.

Later the Prince took to the mountainside of Snowdon to see first-hand work on one of his favourite projects.

He viewed work taking place on the Hafod y Llan estate, above Beddgelert, which was bought for the nation by the National Trust two years ago, after Welsh actor Sir Anthony Hopkins donated �1m to the appeal.

Access

The appeal raised the asking price of �3.65m in only 87 days, including a donation from the Prince.

Aides said the Prince had expressed a wish to see for himself work taking place on the land, which forms about one-third of the Snowdon range.

The purchase by the National Trust ensured continued public access to large parts of Snowdon.

National Trust property manager for the area Richard Neale accompanied the Prince as he climbed to around 1,000ft on the mountainside.

"He is a farmer and knows the problems facing farmers," Mr Neale said.

On his way the Prince stopped to chat to four estate workers carring out repairs to a dry stone wall before returning to farm buildings to watch a demonstration of sheep shearing.

On Monday, the final day of his Welsh tour, Prince Charles is due to open the Royal Welsh Show at Llanelwedd, Builth Wells.