Carreglwyd is a Georgian country house, on the northwest of the Isle of Anglesey, about 1 km NW of Llanfaethlu in Wales, at grid reference SH309878.

The land was owned by the Tudors of Penmynydd, but they forfeited the estate to the family of Griffiths of Penrhyn during the Glyndŵr rebellion in the 15th century.

During the following generations Mary, then her son Holland Griffiths, were responsible for a lot of the remodelling, which continued until the 19th century.

He married Emma Mary Carpenter, granddaughter of Sir John Thomas Stanley, 6th Baronet of Penrhos, Anglesey.

Emma married Sir Chandos Stanhope Hoskyns Reade, 8th Baronet of Shipton.

The estate, then called Ty'n y pant,[4] was owned by William, who was evicted in 1544 only to be reinstated by 1559 for the price of £700 (equivalent to £300,000 in 2023).

[6][3] Another William Griffiths, the Chancellor's grandson, made further alterations in the late 17th and early 18th centuries, the oldest of which remains in the southwest side of the house.

As an heiress, Mary's share vastly expanded the estate, and additions were subsequently added, including stables, a laundry, a walled garden, and a main gatepost.

There is a lawn with lime, oak, and sycamore trees lined with a garden lake with woodlands.

The electronic music festival hosts 5,000 attendees, a number first achieved in 2013, and it attracts musicians from around the world.