Their visit to South Wales extended to three days and the primary reason for their visit was to lay the foundation stone of the National Museum of Wales in the City of Cardiff, on the 26th of June.

The Royal couple had expressed a wish to see thesocial conditions of the area and Sir W.T. Lewis (later Lord Merthyr)  arranged a tour.

On the 27th of June they travelled on the Royal Trainfirst visiting the Lewis Merthyr Colliery, Trehafod, then on to the Mines Rescue Station at Dinas. The tour  then continued by train through Pontypridd, Llancaiach, Bedlinog, Cwmbargoed, to Caeharris (Dowlais) Station, then into the Dowlais Works.

They entered the works on foot, through the "Coal Arch" which had been specially constructed by Dowlais Works' Craftsmen for the occasion. Luncheon was served in Dowlais House, the old home of the Guest family. The Distinguished guests were entertained during lunch by the Penywern Male Voice Choir, conductor Edward Thomas.

They were then conducted around  the works by Sir W.T.Lewis   and Mr. Arthur Keen. Visiting the Blast Furnaces, the Bessemer Plant, Goat Mill, Sleeper Mill, Sole Plate Mill, Fishplate Mill, and the Siemens Plant.

The King and Queen then left Dowlais Works through the "Steel Arch" which had also been specially constructed by Dowlais Works' Craftsmen for the occasion, and proceeded to Merthyr in their own Daimler car, to arrive at the Town Hall steps at 4:00 pm where Sir W.T.Lewis presented them to the Mayor and Mayoress, Mr & Mrs J.M. Berry.