sentences:  Located on a prominent ridge overlooking the River Liffey (previously known as the "Ruirthech", "running swiftly"), this settlement was easily defended and ideally situated to take advantage of the ford, which lay just 100 metres away.The name ford of hurdles – "Áth Cliath" in Irish – suggests that, to facilitate travellers who wished to cross the river dry-shod during low tide, the inhabitants of this settlement constructed a lattice-work of interlaced osiers – "hurdles" – and secured it to the muddy bed of the river, perhaps making use of the fortuitously placed Usher's Island in the middle of the stream.It is also possible that a series of hurdles used as fish-traps were placed along the banks of the river.