This mid 12th century stone keep perches atop an earlier motte in a small wood overlooking the River Llynfi and Talgarth.
Bronllys was founded around 1100 by Richard Fitz Pons, an Anglo-Norman lord. To the north are two baileys each with a bank and ditch. The sites of bastion towers may be detected where there are breaks in the bank and ditch of the outer bailey. There is no remaining trace of any buildings within the walls apart from the round keep, which still towers 80 feet above the motte, though legend tells of a secret underground passage from the castle to Talgarth Tower.
Historic documents also tell us that a large piece of masonry fell from Bronllys Castle and changed the course of history in the Welsh Marches, killing the last male heir of Miles of Gloucester.
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