For Christians, it is the heart of the Holy Land: the city over which Jesus wept and where he was crucified, buried and resurrected.
But despite Jerusalem being central to the faith, Christians there are relatively passive, standing back while others fight over the most hotly disputed piece of land on the planet.
The eternally tragic nature of this division is perhaps best captured in the Talmud, the text on Jewish law written in the second century BC: "Ten measures of beauty gave God to the world: nine to Jerusalem and one to the remainder. Ten measures of sorrow gave God to the world: nine to Jerusalem and one to the remainder."
For beautiful though it is, anyone visiting the Old City of Jerusalem is immediately struck by its complicated and divided nature, with its Jewish, Muslim, Armenian and Christian quarters, its churches, mosques and synagogues competing for space, and the Church of the Holy Sepulchre, Dome of the Rock and Western Wall all ranged within a stone's throw of one another.
For as well as being central to the world's three monotheistic religions, Jerusalem is also deeply political, and at the heart of what is probably the world's most intractable conflict.
Next year sees the 50th anniversary of the Six Day War and the occupation by Israel of the Palestinian Territories including East Jerusalem. Now we know that under a Donald Trump presidency a two-state solution is not on the cards any time soon.
Trump delighted Israel's right-wing prime minister Benjamin Netenyahu yesterday by telling him during a lengthy meeting that if he wins on 8 November, the US would "recognise Jerusalem as the undivided capital of the State of Israel."
The US, the UN and almost every country in the world currently refuse to accept that Jerusalem is Israel's capital, with most major embassies functioning in Tel Aviv. International consensus is that East Jerusalem — having been occupied militarily in the Six Day War and then unilaterally "annexed" — is occupied territory, just like the West Bank.
A statement from the Trump campaign team said that the candidate agreed with Netenyahu that peace could only be achieved when "the Palestinians renounce hatred and violence and accept Israel as a Jewish State".
If there were any doubts over Trump's commitment to Israel, this one-sided emphasis will have laid them to rest.
Trump's rival Hillary Clinton also met with Netenyahu yesterday, issuing a more balanced statement saying that she backed a two-state solution "that guarantees Israel's future as a secure and democratic Jewish state with recognised borders and provides the Palestinians with independence, sovereignty, and dignity".
But it was Trump's comments about Jerusalem that are making headlines around the world, not least in Israel.
It would be wrong to make the – arguably racist – assumption that this will swing the Jewish vote in the US, which polls suggest is by a solid majority Democrat, though it may help Trump among voters with dual Israeli and US citizenship, especially in the settlements, which could be as many as 400,000. Trump's campaign is being helped there by the Israeli right, and the pro-Netanyahu newspaper Israel Hayom is giving Trump consistently supportive coverage.
But the real long-term issue is that a fully Israeli Jerusalem is a major stumbling block for the Palestinians when it comes to a two-state solution, which, of course, is why successive presidents once in office have rejected the concept.
That does not – and should not – mean that Jews would not have access under any agreement to their own holy site, the Western Wall of the Second Temple. All sorts of solutions have been suggested for that under a shared Jerusalem.
It is not unprecedented for presidential candidates to make similar promises, only to go back on them once in office. But in Trump's case, it is easy to imagine him sticking to his pledge. Netenyahu – who critics argue does not want a peaceful solution to the conflict and instead seeks merely the retention of the status quo – is likely to see to that.
Which would mean that peace in Israel and Palestine would be all but impossible for the foreseeable future. And that is bad news for Palestine, Israel itself and the rest of the world.
