Answer:
   
   According to tradition, the Jews are commanded to worship at the
   Temple (Beis Hamikdash) at the place G-d specifies. When this central
   site is extant, sacrifices may be brought only there. Also, Jews are
   commanded to go to the central site for the three "pilgrimage
   festivals", it is the only place where the Pesach sacrifice may be
   eaten, and it is the only place where the "second tithe" may be eaten.
   After David united the tribes into a kingdom, he conquered the city of
   Jerusalem and made it his capital. He then wanted to build the temple
   rather than leaving the ark in the temporary quarters it had been in
   until that time. G-d informed him that while he was not allowed to
   build the temple, his son, Solomon, would, and that temple would
   remain the central site for the Jewish people.
   
   After the temple was destroyed the Jews were not allowed to go back to
   bringing sacrifices at local altars (called bamos or high places).
   Thus, the second temple had to be built on the site of the first. When
   the second temple was destroyed, the restriction still held. Thus,
   according to tradition, it is the only place where the temple can be
   rebuilt when the Moshiach comes.
   
   In the time of Avrohom, the city was the center of the remnants of
   monotheism from the days of Noah. It was the site of the Yeshivah of
   Shem and Ever (Noah's son & grandson) where they taught about G-d and
   the laws G-d had given to Noah.