Archaeologists have never been completely satisfied with the term "hill fort" for the mighty earthworks that encircle 2,000 British hills and date mainly from the Iron Age. For them, it conjures up entirely the wrong kind of image - of Asterix-like Ancient Britons holding out against the armoured might of Rome. In most cases, there is no evidence of conflict or of defensive use.
Most seem to have enjoyed long and peaceful lives as airy townships commanding some of the finest views in Britain. That's certainly the case with Tre'r Ceiri, "the Town of the Giants", from which the all-encompassing view extends many a mile south across the shimmering waters of Cardigan Bay to Mynydd Preseli, the source of the Stonehenge bluestones.
To the west, across the Irish Sea, is the dim blue outline of Ireland's Wicklow Hills. Nearer at hand, the serrated skyline of Snowdonia's peaks ranges along the eastern horizon, with the west coast of Anglesey marking the north. Many believe this to be one of the finest panoramas in Wales.
Our walk starts from a gate on the B4417 Llithfaen road, a mile south of Llanaelhaearn, where there is limited roadside parking. Walk up the signed footpath which follows a wall and through a gate, turning left in front of a prominent rocky outcrop to reach the western shoulder of the hill.
Keep right now and climb more steeply until you reach the still-impressive ramparts of the fort which crowns the hill in front. These ramparts, with their clearly visible entrances and staggered gateways, are still up to 15ft (5m) high in places, and represent some of the most well-preserved Iron Age hill forts in the whole of Britain.
It is worth spending some time exploring the plainly- visible hut circles among the heather, admiring the view, and wondering whether the Iron Age population felt the same sense of awe as we do at these magnificent surroundings.
Archaeologist Dave Hopewell has spent almost every day of the past seven years trekking up to the 450m summit, and he is certain that it was the view as much as anything that persuaded the first settlers to build the massive walls. "There is no doubt in my mind that the physical situation of Tre'r Ceiri was the cause for its construction. Working on it every day as we did, the view never ceased to amaze us. They certainly knew their viewpoints."
Archaeologists estimate that this lofty hilltop could have supported a population of up to 400. Dave and his colleagues have established that it was probably continuously occupied over many hundreds of years, as buildings were re-used and divided to create "semi-detached" dwellings, which would have been roofed with turves or thatched with heather.
After your exploration of the fort, drop down on a narrow path to the col that separates Tre'r Ceiri from the reigning summits of Yr Eifl (564m) to the west. Heading due west, the path climbs steadily to the summit cairn and trig point, and another outstanding view across the Irish Sea.
The valley immediately below to the west is known as Nant Gwrtheyrn, and is said to take its name from the 5th-century leader, Vortigern, who, according to legend, had his headquarters here.
Now turn south from the summit, following a drystone wall down through the rocks and heather towards the conical hill of Mynydd Carnguwch across the B4417 and down to a stile. Cross the stile on the left and continue downhill bearing left towards an old sheepfold, where you regain your outward route back to the road again.
The practicals
Tre'r Ceiri is the easternmost summit of the prominent, triple-topped Yr Eifl ("The Fork") which lies on the northern side of the Lleyn peninsula about 20 miles south-west of Caernarfon in north Wales. The walk is only about two miles long, but involves an ascent of about 300m (1,000ft) over rough moorland and heather, so stout footwear and waterproofs are required. The best map is the Ordnance Survey's 2in to the mile Explorer No 13, The Lleyn Peninsula, East. The nearest sizeable town is Pwllheli on the south coast, where the TIC is at Min-y-don in Station Square (open Monday-Saturday, 10am-4.30pm during the winter, 01758 613000). A recommended pub for a well-earned pint after the walk is The Rivals Inn in Llanaelhaearn (01758 750669), and good B&B accommodation can be found at the Plas yr Eifl hotel (01286 660781) in Trefor, to the north of Llanaelhaearn, just off the A499 Caernarfon road.
