Western Wall stone: 14 metres and 600 tonnes If you have time to do just one thing in Jerusalem, take the
Western Wall tunnels tour, a snip at just NIS 25 (US$6.50), but be sure to book in advance.
Marvel at a single stone which is 14 metres long and weighs 600 tonnes, which was carved out of a nearby quarry more than 2,000 years ago when the walls were constructed under Herod the Great. Walk underground through the small area directly in line with the Foundation Stone on the adjacent Temple Mount, said to be the location of the Holy of Holies in the original Jewish Temple, built by Solomon 3,000 years ago.
Since this part of the Western Wall, now situated perhaps 15 metres below street level, is the closest point that observant Jews can get to the Holy of Holies, it is set aside for brides who wish to pray on their wedding day, so you can expect impromptu cries of "Mazel tov!" to break out among your group as brides (and grooms) shuttle back and forth on their big day. The deal is that, since men get a bigger space at the open, or "Wailing", part of the Western Wall, while Jewish grooms are permitted to come down into the tunnels to get closer to their most sacred site, they are not allowed in the little alcove which can house only around six people at a time.

Western Wall: Brides' Prayer Room
Interestingly, if you visit the Western Wall tunnels in seven or eight years' time, you'll be walking another 10-12 metres lower, as excavation work is slowly recovering the level at which people walked around in Jesus' time.

Arches supporting the Arab Quarter in the Old City
So, how did the Old City above get raised around 25 metres during the last 2,000 years? Quite easy, really. The Arabs built two sets of arches above the original ground level so that they could walk straight onto the "Mount" (their Haram). Thus, it's only tourists, and Jews, for that matter, who need to take the long walkway that ascends from the Dung Gate to the south-west corner of the Temple Mount. The admission times, especially out of season, are quite restricted, and the queues very long. Add to this the fact that non-Muslims are not allowed to enter the Dome of the Rock or the Al Aqsa Mosque, and you can see why quite a few people, including me, decided to give Herod's
enormous platform a miss.
Just a few hundred metres south of the Temple Mount, to which it was once connected by a long staircase, part of which is publicly accessible, the
City of David is another trip very much worth making. The guided tour takes two and a half hours (twice the length of the Western Walls tour), and is, this being Jerusalem, where the bar for becoming a tour guide is set very high with no Welsh exam board to ease your passage, both informative and genuinely interactive.

Al Aqsa Mosque from City of David
Archaeology is as much propaganda tool as science in Israel, but for all that the finds at this site (lower than many of the surrounding hills for the simple reason that you cannot easily access water if you've planted your citadel on one of the highest outcrops) are impressive, supporting the hypothesis that David established his capital here after he kicked out the Canaanites.

City of David tunnels
The City is very much a work in progress, like the Western Wall tunnels site, with a cacophony of sounds ascending from the depths below – the infernal aspect accentuated by the vivid orange light that blazes forth through gaps in the superstructure.

Excavations at City of David
Take a pair of water shoes along and you can walk through Hezekiah's tunnel, which carried – indeed, still carries – that most precious of elements 500 metres from the Gihon spring to the pool of Siloam. This is not for the claustrophobic, those with a fear of the dark (the City of David shop sells keyring torches for a few shekels) or the infirm, with the height of the tunnel as low as five feet in some places, but it's well worth doing. (Those with a fear of water needn't get too concerned, as the stream is only a couple of feet deep at most.)

Arab village of Silwan (Siloam) from City of David
Built 2,700 years ago, no one is quite sure how the tunnellers from either end managed to meet up in the middle. My belief, based on evidence garnered just 20 years ago during the construction of Le Tunnel sous la Manche, is quite simple, and, I think, irrefutable. They weren't French.