Traces of ancient civilisation, including from the Bronze Age, are to be found in the vicinity of Castlemartyr. This includes a group of tumuli (or barrow mounds), including three examples in the townland of Ballyvorisheen.
There is also evidence of the early inhabitants' attempts to defend themselves and their livestock against marauders and the threat posed by wild animals. These defences were in the form of ringforts (or raths), which were circular earthworks used as dwellings and farmyards. Examples of these structures are to be found in the vicinity of the village.
Castlemartyr today is known for Castlemartyr Resort, which offers local spa treatments and golf breaks, or Swan Lake Bed & Breakfast and for many fine food outlets such as Castlemartyr Village Greengrocer and Pubs such as The Hunted Hog