Day 1
The border town, Monmouth, is a good place to start. It was the 12th century Benedictine Monk Geoffrey of Monmouth whose book 'Historia Regum Britanniae' first popularised the Arthurian Legend.
Continue to Chepstow Castle in the Wye Valley where, according to legend, Arthur and his knights are said to be sleeping in a cliffside cave below the Norman castle.
The M4 motorway takes you to Neath and the nearby Craig-y-Ddinas, an extensive cave system that meanders beneath Dinas Rock. Here Arthur and his knights are said to have been seen guarding a huge treasure.
Day 2
A drive through the narrow country lanes of Gower brings you to Arthur's Stone at Cefn Bryn, an ancient burial chamber.
Head towards the romantic ruins of Dinefwr Castle, two miles from Llandeilo. Edmund Spenser in the 'Fairie Queen' says Merlin communed with spirits in a cave in the hill below the castle.
Your next stop is Carmarthen (Caerfyrddin), named after Merlin who was said to have been born here. At Merlin's Hill Centre just outside the town, you can take the path up to the Iron Age hill fort to the place where, according to local legend, Merlin lies.
Day 3
From Carmarthen head towards Machynlleth, then continue along the Dovey Valley. This is the area where Arthur is said to have fought his final Battle of Camlan. A possible battle site is hinted at by the existence of two places called 'Camlan'. One is at Dinas Mawddwy, and the other further up the valley in Cwm Cerist.
Day 4
At Llyn Dinas, near Beddgelert, Arthur's Knight Owain battled with a giant by the lake. A monster reputedly lived in the Llyn Barfog until Arthur threw a chain and killed it. Arthur is also said to have killed a giant called Rhitta on Mount Snowdon, and Bwlch y Saethau (The Pass of the Arrows) is the scene of a fierce battle between Arthur and his enemies. Arthurian treasure is said to be buried at Marchlyn Mawr near Llanberis.
Continue eastwards to Ruthin where Arthur sought revenge after he was wounded by an enemy called Huail. When they met again, Arthur beheaded him on a boulder which now stands in Ruthin's Peter's Square.