The True Story
When King Solomon built the Temple he did it in a very special way. As we have seen recently in the Gulf War Saddam Hussein's palace had also an underground palace so when the palace above ground was destroyed, he moved into the underground palace. Solomon built the Temple the same way. There was a whole other Temple built underground, exactly underneath the upstairs Temple. The Holy of Holies underground is directly below the upper Holy of Holies. When the Kohanim (priests) saw that Nebbucadnezzar was about to enter the Temple, they and the Levites moved the Holy Ark and various other utensils to the underground Temple. Therefore the Temple is still there in full Holiness.
The way to the underground Temple was thru tunnels designed by King Solomon the wisest of men. So they are impossible to find and impossible to go thru. So the Temple never really stopped. It has always been there and is still there now waiting for the Moshiach (Messiah).
Aish HaTorah's Tunnel Tour
In front of the Western Wall of the Temple Mount in Jerusalem, an incredible labyrinth of tunnels, arches, and passageways remained untouched for centuries. At last, revealed through extensive archaeological excavations during the last few decades and culminating in the explosive opening of an exit in autumn of 1996, the Tunnels beckon us to enter...