ANCIENT COIN WITH TEMPLE FACADE

The silver shekel/tetradrachma struck by Bar Kochba 

What's the evidence about the Temple of Jerusalem built by Herod the Great? How do we know what it looked like?

Modern reconstructions of the facade of Herod's Temple are based on the image found on a coin struck by Bar Kochba, leader of the revolt in 132 AD - fifty years after it had been destroyed by the Romans.  

But we also know that Herod followed the original design and dimensions of the Temple very carefully.

He had to.

When Herod first proposed rebuilding the Temple, there was opposition. People were afraid he would pull down the old Temple and replace it with a pagan temple. Or perhaps when the old Temple was gone, Herod would find he had run out of money and abandon the project on the grounds of expense.

To overcome these objections, Herod promised he would follow the original design, duplicating it. He would not pull down the existing Temple until everything was ready to build the new Temple.

Every piece of stone or wood was acquired before building began, and pre-cut off-site so that it only needed to be assembled at the Temple site. 

 The tetradrachma was used to produce this model of the Temple of Jerusalem

On the subject of coins: some of the coins minted during the reign of Herod show a star on them (see images below).

This may well be the star which, according to Balaam's prophecy in Numbers, will come out of Jacob, to usher in the Messianic coming.

Herod probably thought that, if anyone should be declared the Messiah it should be himself, as de facto heir to the House of David. Some of his courtiers told him he was a member of the House of David, and he would have wanted to believe them.