A few words about the lost treasure of The Expedition.

For the record, the treasure that went missing on the "night of sorrows" has yet to be accounted for. Remarkable when one considers that the vanished gold, silver and jewels constituted perhaps half of the largest treasure-trove ever amassed in the New World. Among the more notable items that vanished were gold collars, a life-sized alligator's head of pure gold, solid wheels of gold and silver in different sizes, and countless precious and semi-precious gems.

Some experts argue that the bulk of the plunder was abandoned and sank into the muck of the lake - to be buried under rubble when Cortez conquered and razed the city a year later. To their way of thinking, there’s an awful lot of gold and jewels still sitting under one of the main roads into Mexico city.
Eyewitnesses refute that. One of the reasons any Spaniards survived the massacre at all, was because many of their Aztec tormenters stopped to retrieve booty. The Aztecs themselves tell of recovering everything they could in the days after the massacre, including armor and weapons. It wouldn’t have been hard, the lake wasn’t deep and the beds around the causeway could easily be searched by divers holding their breath. Personally, I can’t imagine that Cortez didn’t have a damn good look at the lake-bed before allowing it to be filled in–or else he knew that the treasure was already recovered. Cortez was as thorough in his plundering as he was in destroying things.

Generations of treasure hunters have searched for the lost hoard, one President of Mexico even dragged the bed of the dried lake trying to find it, to no avail. One legend has it that before Cortez returned to besiege Tenochtitlan in 1521, the Aztecs stashed the treasure in the hills surrounding the lake. 
I surmise that maybe they went farther afield.

While the lost treasure is fact, first-hand accounts of what happened to it in the aftermath of the night of sorrows are conflicting – including the Aztec's. It’s little wonder. By the time Cortez licked his wounds, reinforced and marched on the Aztec capital again, the native populace had suffered a decimating smallpox epidemic. A disease unknown in the Americas before the invaders came. Tens of thousands died. The Empire of the Aztec was already disintegrating by the time Cortez returned to conquer Tenochtitlan. After building a fleet of small warships to control the lake, it took eighty days for the Conquistadores to subjugate and level perhaps the most beautiful city on earth – block by block. The lost treasure was not among the spoils.