(from Ráth Éanna) is that it means the ringfort of Éanna, an early local chief, another (Ráth Eanaigh) is that the name derives from eanach, an old Irish word for marsh or swamp, or for a passage through a swampy area. Yet another (deriving from Rath Ain Abha) comes from "Noble Fortress of the Sea". Locally, most use Ráth Éanna while officialdom now tends towards Ráth Eanaigh. Until the mid-20th century, many local residents pronounced the English language name as something more like Rahenny or Rathenny, as it was mapped in the 18th century, or Ratheny. Although there is a range of similar names (such as Rahanna), the name Raheny is nearly unique in Ireland, occurring in just one other locality, a portion of the rural town of Lusk. This once-significant monastic and civil centre in north County Dublin is not very remote but no connection between the two locales is known. Natural features In addition to the Santry River (historically Skillings Glas), Raheny is also crossed by the Naniken River (previously parts of it named Ballyhoy after a Raheny townland through which it passes), the Fox Stream and the Blackbanks Stream, all monitored by Dublin City Council. The Santry and the Naniken are shown on many old maps, and one or other of the other two sometimes also appear. The Santry comes from Harristown and Dubber, north of Ballymun, and passes through eastern Santry, and Coolock, then between Harmonstown and Edenmore, to reach central Raheny and then flow on to the sea; it is in the open for most of its course. The Naniken, now culverted for more than half its length, flows from central Santry through Artane, then passes under the railway line in a syphon. Its line is marked by a disused lane from Ennafort to the Howth Road, it passes under Ballyhoy Bridge (now hidden under the tarmac of the main road) and comes out of the culvert at the edge of St Anne's Park, and forms a feature through the park. From partway through the park, its course marks the boundary between Raheny and Clontarf. Both the Fox and Blackbanks Streams flow from the limestone area above Station Road (which used to hold caves and quarries), one either side of the steep Belmont or Mount Olive hill on Station Road; both flow underground. The Fox Stream runs through Walmer lands, under Tuscany Downs, but is