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.
Holiday Haunts on the West Coast of Clare by H.B.H

There are also considerable remains of the old castle of Lisdoonvarna, with its terraces, garden walls, and fortifications ; it was formerly the property of the Davorens, an ancient and powerful family in Burren, but now belongs to the Stackpoole family. On the demesne of Rathbane are several very powerful mineral springs, hitherto erroneously called the LISDOONVARNA spas, one of which is celebrated as being one of the strongest chalybeates in the kingdom : it contains so large a portion of iron, that in a few seconds it stains with a ferruginous colour any substance with which it may come in contact ; and has been found peculiarly efficacious in hepatitis, consumption, scorbutic and bilious affections, and rheumatism. Near this is another spring, which on analysis was found to contain, in addition to the iron, considerable portions of sulphur and magnesia ; the water is used with great benefit as an aperient. On the opposite side of a deep ravine, is a spring powerfully impregnated with naphtha, the exhalations of which taint the surrounding air ; silver thrown into the water is instantly changed to a deep gold colour ; and the water has been used with success as a cure for cutaneous diseases and for rheumatism. About a furlong further up the ravine, is a fourth spring, called the Copperas well ; it has not been analysed, but has been used externally from time immemorial with effect as a cure for ulcers. The Rathbane mineral springs, under the appellation of the Lisdoonvarna spas, have been known and appreciated for centuries; they are situated in deep ravines at the base of lofty hills of black slate, between the strata of which are found large quantities of bright metallic ore resembling silver ; but from the bad state of the roads, and the want of proper accommodation, they have been comparatively neglected by invalids. Several cottages have, however, been recently built in the vicinity of these waters for the reception of visiters; and if the proprietor continues his improvements, and a facility of access be afforded, this place will probably become one of the most frequented spas in Ireland.  Samuel Lewis, 1837