Herod tore down the Second Temple and rebuilt it from scratch. Not because it was falling apart. Because it wasn't grand enough for him.
According to Josephus in Antiquities XV, Herod announced the project to a skeptical Jewish public around 19 BCE. The people were terrified he would demolish the existing sanctuary and never finish the replacement. So Herod made them a promise: he would stockpile every piece of material before a single stone was removed. He gathered a thousand wagons for hauling stone, trained ten thousand skilled workers, and even had a thousand priests learn masonry and carpentry so that only ritually pure hands would touch the inner sanctum.
The sanctuary itself went up in eighteen months. The surrounding courts and colonnades took eight more years. The result was staggering. Herod doubled the size of the Temple Mount platform, engineering massive retaining walls that still stand today as the Western Wall. He clad the facade in white stone and gold plates so thick that at sunrise the Temple blazed like a second sun. Visitors who stared directly at it had to look away.
The Royal Stoa along the southern wall stretched eight hundred feet long with columns so wide that three men linking arms could barely reach around one. Josephus claimed anyone who had not seen Herod's Temple had never seen a truly beautiful building.
There is an ancient tradition that during the entire construction, rain fell only at night so the work was never interrupted. Josephus reports this as something handed down from earlier generations, a sign that even heaven cooperated with the project. The dedication featured three hundred oxen sacrificed in a single day, and it happened to coincide with the anniversary of Herod's coronation. One celebration swallowed another, and the nation rejoiced, at least for a moment, under the reign of their deeply complicated king.