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Remains of East Blockhouse N of Rat Island is a medieval blockhouse situated in Wales, protected by Cadw under reference PE398. Built upon bedrock composed of Pridoli mudstones, siltstones and sandstones, the structure occupies a locality with significant strategic potential. The Pridoli geology underlying the site dates to the final period of the Silurian era, providing a stable foundation of undifferentiated sedimentary deposits that characterises much of the Welsh landscape.
Medieval blockhouses served as fortified strongpoints, typically constructed to control movement along waterways, defensive lines or critical territories. Their compact design made them effective garrison posts requiring minimal permanent occupation whilst maintaining strategic presence. The positioning north of Rat Island suggests this blockhouse was positioned to monitor passage or defend a locality of importance to medieval Welsh or Anglo-Norman interests.
Today the structure survives only as earthwork remains, testament to the medieval fortification practices common across Wales during the period of intensive castle-building and territorial consolidation. Its protected status ensures preservation of this modest but significant component of Wales's medieval military heritage, recording the engineering solutions adopted by medieval builders working within the constraints of local geology and landscape.
Remains of East Blockhouse N of Rat Island is a scheduled monument protected by Cadw under reference PE398. View the official record →
Remains of East Blockhouse N of Rat Island is a medieval blockhouse situated in Wales, protected by Cadw under reference PE398.
Remains of East Blockhouse N of Rat Island dates from the medieval period, and is classified as a blockhouse. It is one of over 32,000 scheduled monuments protected across the UK.
Remains of East Blockhouse N of Rat Island is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is PE398.
Several scheduled monuments lie within 10 km, including Promontory Fort at Sheep Island (1.1 km), Angle Castle (2.4 km), The Tower (2.5 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Remains of East Blockhouse N of Rat Island's history, each drawn from the record and mapped to the exact spot:
Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.
Remains of East Blockhouse N of Rat Island stands on Pridoli Rocks (Undifferentiated), bedrock that formed in the Pridoli. The rock here is mudstone, siltstone and sandstone.