Start at the Billy Byrne monument, in Wicklow's Market Square. The statue sums up Irish nationalism over the last two centuries. Billy Byrne was a member of the 1798 uprising against the Crown, but unlike most of the rebels, he was a Protestant landowner. To make an example of him, he was rapidly tried and sentenced to death. A century later, this monument was erected in his honour - while Ireland was still part of Britain.
Begin by descending Quarantine Hill - there is no road sign, but this street lies between the Ros Duin pub and the gents' toilet. You join Castle Street, passing Wicklow's modest harbour to the left. The road leads to an old stone arch, one of the few remains of the fortress that once dominated the harbour entrance. From the pair of cannon, look back across the town and north to the magnificent Wicklow mountains.
So far you have covered barely half a mile, but the pace quickens on the springy turf. A few white posts indicate the route, squeezed along the edge of the cliff by the adjacent golf course. Climb over a footbridge, then cross the mouth of a cove. The grass gives way temporarily to a track; turn right at the next white post. The next bend of the walk takes you into the firing-line of a fairway, so you may need to negotiate safe passage with the golfers.
Two miles in, the terrain becomes rocky. You ford a small stream stained red with iron oxide. Ten minutes later, you reach a fork; go right through a short, narrow canyon decked with ferns. As you emerge, there is another fork; again bear right, to a gate with a warning "Bull loose with cattle"; pass to the left of the gate.
To the seaward side, a tongue of rock curls into the water. Soon two of the lighthouses on Wicklow Head come into view. Cross a flattened wall and broken fence, then climb to a road where you bear left towards the lighthouses. Go through the red gate to the taller of the pair, an octagonal structure reaching 100ft into the invigorating air above Long Hill, on which it stands. It has an extraordinary history, having begun life in 1781 as one of a matching pair; in the days before flashing machinery, the presence of two lights helped mariners distinguish Wicklow from other headlands.
This, the uppermost light, was too high for an outcrop often smothered in fog. To make matters worse, a lightning strike in 1836 gutted the interior. Yet, because the handsome tower had become such a familiar daylight sea- mark to mariners, it was preserved, while its sibling became decrepit and was dismantled to build the keepers' cottages (now also ruined) in the saddle of land between Long Hill and the headland. The small tower that sprouted there is now also obsolete. Meanwhile, the octagonal lighthouse gets a new lease of life in a fortnight when it opens as the latest addition to the Irish Landmark Trust; it has been handsomely kitted out to sleep six.
From here, I strongly commend the optional loop down to the shore. It involves a steep, five-minute descent: follow the path that winds down from the octagon, but turn right where a gravel track leads further downhill. With a tad of scrambling, this will take you to the present lighthouse, buried deep beneath the cliff.
The ascent back to the uppermost lighthouse takes at least twice as long, up the twisting roadway. At the top, you have the choice of returning the same way that you arrived - a good option, since the changing views of the coastline repay further study - or via the lane, then road, back into Wicklow Town.
This quicker option begins encouragingly; turning your back upon the sea, for the first 15 minutes you walk straight into satisfyingly archetypal Irish scenery - rolling emerald hills speckled with sheep and cows.
You soon find yourself on a main road; fortunately, this is little travelled but care is still required. Follow the contour around the golf- course water hazard, where a proper footpath begins to run alongside the road. The descent down Summer Hill towards Market Square yields fine views out to sea. The huge grey block on the left is the 300-year-old Wicklow jail, whose 4ft-thick walls once incarcerated Billy Byrne.
Continue across Market Square, your starting point, along Wicklow's curiously split-level Main Street. You reach Fitzwilliam Square, at the centre of which is an obelisk to the other local hero - Captain Robert Halpin.
He ran away to sea aged 10, but was shipwrecked on his first voyage. Undeterred, he went on to become the man responsible for connecting most of the world, as leader of cable-laying missions across the globe. A sharp right along Bridge Street leads you to his birthplace, the welcoming Bridge Tavern.
Map: Irish OS Discovery Series number 56 (1:50,000).
Simon Calder reports from Wicklow for BBC2's Travel Show on 28 July.
From Market Square head due east along Quarantine Hill. At the ruined castle, follow the path along the cliffs. At each of two successive unmarked forks, bear right. Join the lane that leads to the lighthouses. Either retrace your steps, or follow the lane and coast road north to Wicklow Town. Make for Fitzwilliam Square, turn sharp right down to the Bridge Tavern.