Because that is where it is believed the Christ was murdered and because the Israelite were believed to be gods chosen ppl so when they lived there alot happened and now its a historical area <span />
Jerusalem was very important because back than it was known as the city for Jews and so they lived there, worked there, and played there so when the romans came to kill all Jews they attacked and knocked down the cities because they wanted to destroy everything Jew related since it was conflict over religions back than.