Hy-Brasil (Uí Bhreasail) – Phantom Island
Uí Bhreasail · Brasil · O'Brasil · Hy Brazil
Medieval to early modern cartography (1325 – 1873 charted; legend 7th c. Irish immram)·Irish immram myth / Iberian cartography·🇮🇪 Atlantic Ocean west of Galway/Clare coast (~321 km west), Ireland
About
About Hy-Brasil (Uí Bhreasail) – Phantom Island
Circular phantom island (Uí Bhreasail = descendants of Breasal) charted from Catalan Atlas 1325 through Ortelius 1570 to 1873 Admiralty, typically as perfect circle bisected by strait west of Aran (~320 km). Seven-year appearance cycle with immortal inhabitants, reached 1674 by John Nisbet claim. By 19th c. surveys proved Atlantic empty; porcupine Bank shoal may be shallow reality behind distortion. Juvenile 'Rendlesham coordinates' internet myth ties Hy-Brasil to UFO hoax – exemplifies phantom island persistence.
Why it mattersMost durable Atlantic phantom island (500 yr); demonstrates pre-longitude cartographic inheritance errors and isle-of-blessed literary spatialization.
Open questions
Mysteries & theories
Mysteries
- 01Why perfect circle bisected? Perhaps artistic convention for isle-of-Brazil wood dye trade label
Theories
- 01Porcupine Bank (shallow to –145 m) sighting in exceptional clear air + fata morgana became myth, then cartographically immortalized
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- Not built – cartographic phantom
- Period
- Medieval to early modern cartography (1325 – 1873 charted; legend 7th c. Irish immram)
- Culture
- Irish immram myth / Iberian cartography
- Purpose
- Otherworld island (Tír na nÓg variant) and navigational fiction
- Abandoned
- 1873 British Admiralty finally removes after systematic soundings
- Rediscovered
- 1325 Dulcert chart first circle; persistent 500-year cartography
- Excavation
- Not applicable
1325
Angelino Dulcert Catalan chart circles Brasil west Ireland
1480
Bristol expedition (Ayrton?) fails to find Brasil
1674
Captain John Nisbet hoax letter claims landing on O'Brasil
1873
Admiralty chart deletes after Challenger surveys
On the ground
Structures & features
51.0000° N · 17.0000° W · 0 m · 3 mapped features
Hy-Brasil nominal position (51N 17W)
phantom centerClassic charted locus ~320 km W Galway
51.0000° N · 17.0000° WPorcupine Bank (possible shoal kernel)
bankShallow bank at 53N 13.5W sometimes conflated
53.3300° N · 13.5000° WCatalan Atlas 1325 circle (chart locus)
chartMap depiction origin point Mediterranean charts
39.9000° N · 4.0000° E
Gallery