Is it simply because it is a larger city in a land where the Abrahamic religions grew from? It just seems interesting that the same city ended up as the location of the Jewish temples, the crucifixion of Jesus Christ for Christians, and so many places of importance for Muslims. Is that just coincidental, or are they necessarily related?
Obviously the religions' histories are intricately tied, so I guess it shouldn't be that odd, but I'm curious if there are any historical reasons why that ended up being practically centered around the same city, or if it just "happened" to be the case.
As you said, Judaism, Christianity and Islam are all three 'Abrahamic' religions. You could not have Christianity or Islam without the original Jewish prophets.
It was the capital of the united Kingdom of Jerusalem, and thus, it is inextricably intertwined with many events and legends. The Temple Mount, for example, is the most sacred site in Judaism. It was the location of the First Temple, where the Ark of the Covenant was housed, before the former was destroyed and the latter lost. It has the 'Foundation Stone' at the very center of the Mount, which lies above a cavern called the 'Well of Souls', as well as the 'Holy of Holies', which was the inner sanctuary of the Tabernacle where God dwelt.
There are many other sites of immense religious significance to the Jewish people, such as the Wailing Wall.
Jerusalem is important to Christianity, because the original Christians were Jews. Jerusalem is the central setting of both the last days of Jesus Christ, his Crucifixion (on the hill of Calvary just outside ancient Jerusalem's walls) and the Resurrection. It was immensely important to the early days of the Church as well.
Jerusalem is important to Islam (though unlike for Jews and Christians, it is NOT their holiest site), because Islam is also an Abrahamic religion. They consider Jesus, Moses, Elijah, etc, to have been prophets, and Jews and Christians to be 'People of the Book'. Islam does not consider itself an entirely new religion. They consider Muhammad to simply be the final prophet sent by God to update everyone on what the final revealed truth is.
The Temple Mount is also supposed to be where Muhammad was brought on his 'Night Journey', and there are other traditions, as with Judaism connecting it to the creation of the world, and as with Christianity, connecting it to the end times.
In addition to all of this, Jerusalem has been the target of many wars and conquests. The (pagan) Romans massacred the city. The (Christian) Eastern Roman Empire lost it to the Islamic Conquest. The Muslims lost it to the Crusaders, and then conquered it back. Shi'ite and Sunni fought over it (though, they were more concerned with Cairo, Baghdad and Damascus.)
It is worth reiterating, that despite Jerusalem's clear importance to Islam, it is Islam's third holiest site at best, with both Mecca and Medina having vastly greater importance. Muslim rulers were not inconsolable over the loss of Jerusalem, and were ready to bargain it away, at least a half dozen times, during the several century stretch of Latin involvement in the Levantine.
Jerusalem has become far more important to the Islamic world in the 20th century, than it has ever been in the past. It has become wrapped up in the traumatic experience of the Arab-Israeli wars.
In any case, as you can see, there is no coincidences involved. They are absolutely related.
Jerusalem is of incredible significance to the Jewish people. The first Christians were Jews, and Jerusalem is the most important location in the Gospels, where the life of Jesus is concerned, especially the parts of it most relevant to the Christian faith. Islam inherited all of that, and then of course, owned it most of the last 1500 years.