This town is a small market and trading centre, local tradition ascribes its name to a land-owning racing enthusiast of the last century (an O'Brien), whose heart was in the racing stables of Newmarket. Dromoland Castle, near Newmarket-on-Fergus.
The O'Briens, of whom Lord Inchiquin is head, moved to Dromoland at the end of the 17th century and remained there until 1962. This was the birthplace of William Smith O'Brien the Young Ireland leader, who was arrested and exiled after the abortive rising of 1848. The most recent house was built in 1862 by James Pain and is now a luxury hotel with its own golf course.

Mooghaun Fort
(Off the N18 road between Newmarket-on-Fergus and Dromoland.)
This famous Iron Age ring fort,
"one of our most remarkable antiquities has three great stone-walls of which the outermost, oval in outline, measures 450 m x 300 m." 0'Riordain, 1942.

Ralahine Castle
A 16th century MacNamara Castle, near Newmarket-on-Fergus, was once the property of the Vandeleur family, and drew attention in the 19th century as the site of a rural co-operative enterprise, the Ralahine Agricultural and Manufacturing Co-operative Association. Unfortunately, Vandeleur ran up high gambling debts and the Co-operative was disbanded in 1833. The castle has since been unoccupied.

On the Northern shore of the Fergus estuary, the village is the site of an 0'Brien castle, built in 1576 and occupied by the Earl of Thomond. This castle could perhaps have given Clare County its name.

Clare Abbey
1.5 km north of Clarecastle, are the ruins of a priory of Canons Regular of St. Augustine, founded in 1189 by King Donal Mor O'Brien. The abbey was occupied until about 1650.

Killone Abbey
(Cill Eoin - St. John's Church)
Today you can see only the remains of this Augustinian nunnery (dedicated to St. John) that was founded by Donal Mor O'Brien, King of Limerick 1180. The holy well of St. John nearby was a place of pilgrimage. The buildings are in a picturesque setting on the banks of Killone lake.
Killone Abbey, lies in the grounds of Newhall House, designed by Francis Bindon (1690-1765) for Charles Mc Donnell, M.P. for Clare in the 18th century.
The house has many interesting features and is privately occupied.