Every structure in this city of unearthly beauty, from the 16th-century Old City walls built by Suleiman the Magnificent to the Hilton Hotel that opened this year, is made of the same Jerusalem stone. It is this exquisite sand-colored limestone, ubiquitous in the Judean desert nearby, that gives the city its ethereal softness and translucence, that sense of having emerged from the very ground on which it grew, like Adam from the dust.

Curiously, the British are to thank for that. Not their architects but their governors. Early in their occupation of Palestine (1917-1948) they decreed that every new or refurbished building here must be clothed in Jerusalem stone. When the Israelis took over in 1948, they kept the law. (And the English language, too, though they wisely jettisoned the food.)Other conquerors have been less kind. The Jordanians, now Israel's best friends in the Arab world, wrested the Old City from the Jews after the Brits left in 1948. They then leveled the Jewish quarter.

When the Israelis returned in 1967, they rebuilt it. With one exception. One synagogue was left a ruin, a monument to what they had suffered here over the centuries.

Nearby is a reminder of a much earlier conquest: an excavation showing a series of stately, well-preserved Byzantine columns in a perfectly straight line. This was the Cardo, the main paved street of Roman-Byzantine times, with pillars and covered shops on either side.

The cardo is a trademark left by the Romans nearly everywhere they went. Many have been discovered in Israel. My favorite is a magnificent one in Beit She'an near the Sea of Galilee. The ruins, the remains of the Hellenized city of Scythopolis, are of vast Ozymandian proportions and pretension complete with cardo, amphitheater, temple, statues, baths and sit-down public toilets (!). Scythopolis stretches out before you, not just immense but pristine. It was destroyed in an earthquake in 749 and never rebuilt - good luck for archaeologists, though hardly for Scythopolitans.

To find such magnificence in Jerusalem, you have to dig. Deep. The Cardo here is a good 20 feet below today's street level. Which means that with every step you take, you are walking on 20 vertical feet of accumulated rubble representing 2,000 years of civilizations now buried underfoot.

Everywhere else, archaeological time is an arrow. Here it is a circle. This is the only country on earth that speaks the same language, worships the same God and inhabits the same land that it did 3,000 years ago.

Which is why the categories of colonialism and imperialism routinely employed in understanding the Arab-Israeli conflict do not apply. Israel is not Australia, South Africa or Hispanic America. The newcomers there were strangers. Dig anywhere in Jerusalem, however, and you'll find coins minted millennia ago with such inscriptions as "Year Two of the Freedom of Israel."

Such underground discoveries don't, of course, solve the Arab-Israeli problem. But they do illuminate it. The solution is obvious: Those who came home and those who in their absence took up residence in that home must divide it up. This is what the Arab-Israeli peace process is all about. But if you want to see why it came about and why it defies conventional understanding, come here - and descend.