Lisdoonvarna takes its name from "LIOS DUIN BHEARNA" the lios or enclosure of the fort in the gap. It is thought to refer to the green earthen fort of LISSATEEAUN (fort of the fairy hill), which lies 1½ miles to the North-East, near the old castle site.

The present town is a comparatively new one by Irish standards, dating mainly from the start of the nineteenth century. It is the only active spa town in Ireland. The beneficial effects of its water were first noted by writers as early as 1740. Lisdoonvarna was established as a tourist centre almost entirely because of its spa. It was the centre around which the town developed. There was no earlier village, just a few scattered cottages. However, the numerous ancient sites and historic remains in the vicinity are evidence of human habitation and activity in the area many centuries before the establishment of the town itself. Ring forts in the vicinity can date from the Iron Age into the Christian era and up to late medieval times. In 1896 James O' Donoghue found the Lisdoonvarna Bronze Pot at Aughiska Beg about five hundred yards from the sulphur well. The Twin Wells are located in a picturesque setting on the banks of the River Aille. They are a source of sulphur and iron water which, very unusually, springs from the one rock.

The opening of the West Clare Railway contributed towards the development of the spa, although the nearest railway station was seven miles away at Ennistymon. This station opened in 1887. The springs were under the direct control of private individuals, particularly the Gutherie family, one of whom became a legendary figure in the life of the spa as Biddy the Sulphur. By 1888 she was dispensing from a neat little pump-house and hotels were competing with each other for business. Dr. Westropp bought out the Gutherie interest in the wells. He updated the dispensing methods and introduced baths. By the turn of the century many fine hotels and boarding houses had been established in the flourishing spa town. An amusement pavilion was provided and people from every walk of life mingled around the wells.

Matchmaking soon became one of the main activities of Lisdoonvarnas holiday-makers. September was, and still is, the peak month of the holiday season and with the harvest safely in bachelor farmers flocked to Lisdoonvarna in search of wives. Matchmakers prospered as matches were contrived and marriages made. The Spa Well also continues to attract the crowds. Today the complex houses a modern recreation centre, a solarium, saunas and keep-fit equipment.