Llanfyllin has a very rich and long history, extending back to the Princes and Lords of Powys. One of which granted Llanfyllin a charter conferring borough status. Llanfyllin's religious history stretches even further than this. This small town has seen violence and rioting during the Tudor and Stuart period, when supporters of rival local dignitaries struggled for ownership of the town. During the 1600s, it saw conflict between Royalist and Parliamentarian. In the last 100 years, Llanfyllin has experienced the rise of Nonconformity, the struggle with the Established Church and it's supporters in the local gentry, the spread of Liberalism among business people, and the efforts of professionals to gain more educational advantages. Llanfyllin certainly has a fascinating past for such a small town.

The Cain Valley Hotel (formerly The Wynnstay Arms) has been Llanfyllin's principal inn for centuries. It was built in the 17th Century and still possesses an imposing 17th Century staircase. The brick front and the Tuscan porch were added around 1800. Until about 1850 it was the Goat Inn, its name indicating an association with the Vaughans of Llwydiarth and Llangedwyn whose coat of arms included a 'goat passant'. Its beer was popularly known as 'goat's milk'.

Across the road is the Temperance Inn (now a convenience store). It was once a Llanfyllin custom on St. Myllin's Day (June 17th) to affix a rope to an upper window of the Temperance and to fasten an earthenware pot to the rope. A live cockerel was put in the pot, which was covered by a cloth. The other end of the rope was then tied to an upper window of the Goat so that the hapless cockerel was suspended over the High Street (known then as Broad Street). Sticks were then flung at the pot and whoever broke it received the released cockerel as their prize.