During World War I (1914 - 1918), the pavilion was a venue that continued to attract and provide high standards of entertainment for the people of the Caernarfon area, and in 1921 the National Eisteddfod of Wales was held there for the sixth time since the year it was built in 1877.

At that Eisteddfod both main competitions in the Poetry Section were won by Caernarfonshire poets. Mr. R.J. Rowlands (Meuryn) born in Abergwyngregyn, Near Bangor, winning the chair and Pwllheli born The Rev. Albert Evans Jones (Cynan) being awarded the crown. Meuryn, a journalist by profession, composed an ode in strict metre "Min y Mor" (By the Sea) where he was able to display his expertise to the full. Cynan on the other hand, in his poem "Mab y Bwthyn" (Son of the Cottage) drew heavily on his Wartime experiences both as a non-combatant stretcher bearer and later as a chaplain. Both poems were extremely popular in their day and were to become for many years test pieces in reciting and penillion singing competitions in subsequent Eisteddfodau.

When cinemas became popular in the 1930’s, and with three of them in Caernarfon, less and less use was made of the pavilion. Nevertheless, concerts, dramas, etc. were performed there, and in one concert, Paul Robeson, the Negro spiritual singer took the stage there in September, 1934, at the time of the Gresford Pit Disaster, Near Wrexham, where 264 miners were killed in an explosion. Paul Robeson happened to be filming in the South Wales Valleys at the time, and had a high regard for the people of the mining communities whom he had met. He was deeply moved by the tragedy and gave a donation of £100 towards the fund that was established to assist the widows and orphans of those who died.

After the concert there were another three meetings of importance held at the pavilion up to World War II breaking out viz. The Caernarfon National Eisteddfod in 1935; secondly one to welcome the three Welsh Nationalists Saunders Lewis, The Rev. Lewis Valentine and D.J. Williams, upon their release from Wormwood Scrubs Prison in 1937, and having been sentenced for an act of protest on behalf of their fellow Welshmen and in the name of peace, by setting fire to a building at RAF Penrhos, Pwllheli; and thirdly the Labour Day Festival of 1938, which was addressed by D.R. Greenfell M.P., in the absence of Clement Atlee. On the three occasions the building was filled to capacity.

At the beginning of World War II in 1939, the pavilion was requisitioned by the government and used as a warehouse, mainly to store food. There also, as the writer can well remember, we as a family were required to go to be fitted with our gas masks, and from then on we had to carry the gas masks everywhere, including to school; school books in a satchel over one shoulder and the gas mask on a piece of string over the other.

The pavilion was on lease to the government from 1939 to 1956. By this time the building had deteriorated considerably and much maintenance work was required on it. The Borough Council felt that it would be impracticable and too costly, and that there was no longer a need for a building of this size, and in 1961 it was decided that the building be demolished, despite the arguments of those who opposed.

It was on October 21. 1961 that the people of Caernarfon bid farewell to the pavilion and in real Welsh style.

The Last Farewell to the pavilion had been arranged by the North Wales Representative of the BBC, Mr. Sam Jones. This was in two parts, firstly in the form of a Hymn Singing Festival conducted by Madam Dilys Wynne Williams and with Mr. G Peleg Williams as the accompanist, and secondly in the form of a Radio Pageant, again arranged by Mr. Sam Jones; the material having been provided by the Chaired Bard of the 1921 Caernarfon National Eisteddfod, Meuryn (R.J. Rowlands), and the producer being Wilbert Lloyd Roberts. Famous names that appeared on the programme included Cynan, Huw Jones, Charles Williams and others and the voices of Megan Lloyd George reading one of her father’s speeches and Jiwbili Young reciting a sermon by Christmas Evans.

It was an unforgettable night as far as my wife and I were concerned. Every item was broadcast live on the Radio, and the UK National News at 10 from London had to be delayed until the end of the programme. We all fought back tears as we left the pavilion for the last time that night, but that which we were witness to can never be erased.