Crannógs of Ireland

A crannóg is usually a partly or wholly artificial island, built in a lake, bog or estuary; unlike the pile dwellings of the Alps, crannógs were built out in the water. The word comes from Old Irish crannóc, a wooden structure, from crann, "tree". Most are mounds of brush, stone or timber, sometimes held in place with timber piles. (Wikipedia, "Crannog" ↗)

In Ireland the largest concentrations are in the Drumlin Belt of the Midlands, North and North-west, and they were most common in Connacht and Ulster, on bogs and small lakes rather than big lakes or rivers. Irish crannógs appear in Middle Bronze Age layers at Ballinderry (1200 to 600 BC), and they were at their height in the Early Historic period, as homes and retreats of kings, lords and prosperous farmers, and sometimes of hermits or metalsmiths. How early they began is still argued: lakeside settlements go back to 4500 BC, but these were not built as islands, and excavations keep turning up crannógs from Ireland's "missing" Iron Age. (Wikipedia, "Crannog" ↗)

Crannog records in the Republic, by county. Northern Ireland: 299 NISMR records typed CRANNOG, shown under their counties below.

Open a county for every record: townland, a line quoted from the survey's own description where it has one, the SMR number (linked to the Historic Environment Viewer) and a map link where the record has a position.

• A record is a survey entry, not a promise that something is there. The Sites and Monuments Record lists sites that are known, reported or marked on old maps, including some that have been destroyed, moved, or were never found when inspected. Each record's own description says what the surveyors saw; read it before you set out.
• Some records have no description uploaded yet, and a few have no usable position; they are marked as such.
• Most sites are on private land. Ask before you cross a field, and leave things as you find them: monuments in the Record of Monuments and Places are protected under section 12 of the National Monuments (Amendment) Act 1994 ↗.
• The Sites and Monuments Record covers the Republic only. Northern Ireland's record (the NISMR) is counted here by county from its open data, by matching the record descriptions; it is not listed site by site and its counts are not directly comparable.
• Some records describe a lake that has since been drained or lowered, so a crannóg may now stand on dry land, or be under water. Read the record's description before you go.
• Northern Ireland: 299 NISMR records are typed CRANNOG; the NISMR's own count, not listed here.

Source: National Monuments Service, Archaeological Survey of Ireland, Sites and Monuments Record, open data via data.gov.ie ↗ (CC BY 4.0); every record links to the Historic Environment Viewer ↗. Northern Ireland: Northern Ireland Sites and Monuments Record (Department for Communities, Historic Environment Division), OpenDataNI ↗.