This afternoon the President, Mrs McAleese, will visit Observation Post 6-41 in the Irish battalion area in central south Lebanon. The post, which has been held by the Irish UNIFIL battalion since the late 1970s, is one of the most disputed and dangerous positions held anywhere by the UN.
Perched on top of a stony hill known only as Hill 880, because its summit is 880 metres above sea level, its principal significance is that it is the highest point in the centre of south Lebanon. This gives whoever holds it a commanding gunnery position from which to bombard the surrounding countryside.
Close to the Irish post the Israeli-backed militia, the South Lebanon Army (SLA), holds the Haddatah compound.
The SLA frequently fires artillery shells at Muslim villages in south Lebanon and is frequently the target of attacks from the Muslim militias.
The post is inside the Israeli-occupied strip of Lebanon along the northern Israeli border. Israel has occupied this eight-mile-wide buffer zone since it last invaded Lebanon in 1982, an invasion in which around 20,000 people were killed.
Israel continues to hold on to the strip of Lebanon despite UN Security Council resolutions 425 and 426 which demand its withdrawal. When the Israelis retreated south they held on to the buffer zone and have installed the SLA as their proxy local government.
Many Muslims, fearing they would be massacred by the mainly Christian SLA, fled northwards, settling in other villages or the sprawling refugee camps dotted along the coastline. The mainly Muslim population of the village of At Tiri, just south of Post 6-41, fled north and only a handful of very elderly people still live in the deserted and overgrown streets.
The Irish have held on grimly to Post 6-41, despite attempts to unseat them by groups seeking the vantage point on top of Hill 880. Irish soldiers have been killed in action defending the post.
The position remains highly dangerous. The requirement that the President and her party don flak jacket and helmet is not for dramatic effect. Irish bomb-clearance teams sweep the road to Post 6-41 for mines every morning before the roads can be cleared for their own vehicles to travel; any non-UN traffic on this road would almost immediately attract fire from the local militias.
The present Irish battalion tour occurs at a time of continuing tension in the area. Since the start of this year about 40 Israeli soldiers have been killed in clashes with Islamic militia in and around the Israeli-occupied strip of land in south Lebanon. There has been a similar number of Lebanese civilian and militia deaths.
Two weeks ago a mortar fired by the Amal Muslim militia landed in one of the Christian villages inside the buffer zone, killing 12 women and elderly men. The SLA retaliated by firing high explosive and phosphorus shells at Muslim villages.
At the funerals of two Muslim militia members last weekend, the Hizbollah (Party of God) leader, Sheikh Nabil Quaq, threatened to attack Israeli settlers in northern Israel if the Israelis or the SLA carried out any further attacks on Muslim villages.
In May last year, 300,000 people, almost all the people of south Lebanon south of the Litani river, were evacuated during a massive Israeli bombardment. The bombing and shelling ended after 102 people, mainly women and children, were killed when the Israelis shelled the UN camp in the town of Qana.
After that bombardment an international committee was set up to try to negotiate ceasefires between the two sides when there is a danger of escalation.
By local standards the area is enjoying a period of relative peace. Many of the Muslim villages have undergone extensive rebuilding, and people who have made fortunes working abroad have returned to build palaces in their home villages, which they use as summer retreats.
In sharp contrast with the bustling Muslim villages in the Irish battalion area, the Israeli-controlled zone has withered socially and economically. In some parts the landscape seems as though unchanged since Biblical times.
The last Irish UNIFIL tour suffered one death, and one soldier, Private Gary Maloney, was badly injured while clearing an Israeli minefield. Five other soldiers were less seriously injured in the incident but recovered sufficiently to return to duties after treatment. However, Private Maloney (23), from Ennis, Co Clare, lost his right heel and his left leg beneath the knee.
In August, the 81st Battalion also suffered the death of Sgt John Lynch, who died in a helicopter crash. He was the 38th Irish soldier to die on service in Lebanon.
Mrs McAleese is only the second head of state to visit this area since the outbreak of civil war in Lebanon in 1975: President Scalfaro of Italy visited in October, to honour the memory of the four Italian airmen who were killed in the same accidental crash in which Sgt Lynch died.
The President is guest of the 82nd Irish UNIFIL Battalion led by Lieut Col Colm Doyle, who received international attention as Lord Carrington's aide-de-camp and as the UN's spokesman during the height of the conflict in former Yugoslavia.
His battalion is two months into its six-month tour of duty. It will be in place when the Defence Forces celebrate the 20th anniversary of the sending of the first battalion to serve in Lebanon in 1978.
Lieut Col Doyle, who served as a captain with the first battalion (the 43rd) in 1978, now returns for the first time as battalion commander. Five other members of the 82nd also served in Lebanon in 1978.
There are 603 Irish soldiers with UNIFIL, of whom 520 will serve in the battalion's area in the interior and the rest at UNIFIL HQ on the coast at Naqoura.
The Irish battalion area is split into three company areas, the most volatile of which is the C Company area around the village of Brashit, which was almost levelled during Israeli bombardment last year.
The 82nd Battalion includes 140 new soldiers who have completed their training and are serving in Lebanon for the first time. Thirteen of these are women.
A few years ago there was increasing concern in the Defence Forces about making up the numbers for the UNIFIL contingent because of a lack of recruits. At one point, sending members of the reserve force, the FCA, to serve was considered.
The government decision two years ago to resume Army recruitment has ensured that the battalion will continue at its full strength of regular soldiers.
In October the Defence Forces Chief-of-Staff, Lieut Gen Gerry McMahon, told a soldiers' representative association he was considering changes in the way the UNIFIL battalion is rotated, from a single six-monthly rotation to staggered or "rolling" rotations of 200 troops at a time every two months. This would reduce the amount of time spent on familiarisation by the incoming battalion.