The Old Oak was probably planted in 1659 to mark the ascension of King Charles 11 to the throne. It became a popular meeting place for local people because the area at the time was quiet and central. It was an important social location but the tree was allegedly poisoned by a man who did not like the noise made by the people gathering there. The mythical character of King Merlin has been associated with the Old Oak since the 19th Century and it is said that he still sleeps under the hill close by the original location. The saying goes that,
'When Merlin's tree shall tumble down
Then shall fall Carmarthen town.'
The story shows the importance of myths and legends in the Welsh culture and highlights the way stories are passed down from generation to generation, bringing this form of oral tradition to life. Myths and legends are enjoyed by children and adults alike. Remnants of the Old Oak can be found on display in Abergwili Museum and St. Peter's Civic Hall for visitors to enjoy looking at and learning about an important part of local Carmarthen history.