This city's position at the midpoint of two bridge
This city's position at the midpoint of two bridges four miles apart, Oldbridge and Bewley, enabled its defenders to protect its curtain walls as well as the West Gate and St. Lawrence Gate from Phelim O'Neill during the Eleven Years War. A later battle here culminated in the losing commander being beaten to death on St. Michael's Mount with his own wooden leg after that man, Arthur Aston, claimed that "he who could take" this place "could take Hell." Over a thousand survivors of the initial breach of the walls here were caught and killed in St. Peter's Church. Most of the losers were deported to Barbados after the literal decimation of its defenders in 1649, two months before a similar action at Wexford. For 10 points, name this fortress on the Boyne where forces of Oliver Cromwell committed a notorious massacre.
This city's position at the midpoint of two bridges four miles apart, Oldbridge and Bewley, enabled its defenders to protect its curtain walls as well as the West Gate and St. Lawrence Gate from Phelim O'Neill during the Eleven Years War.
Drogheda [or Droichead ?tha]