Nice animation, but I bear in mind that stuff that is presented like this is really just hearsay - we don't really know that it was built as presented. It could well have been built as shown - its a plausible hypothesis. But it is also plausible that the bridges were only built in the 18th century. Or maybe they were built 100's of years earlier.
With any historical claims, we should have access to the source to be able to confirm.
On the wiki page that was posted we read:
https://en.wikipedia.org/wiki/Charles_Bridge
"Throughout its history, Charles Bridge has suffered several disasters and witnessed many historic events. Czech legend has it that construction began on Charles Bridge at 5:31am on 9 July 1357 with the first stone being laid by Charles IV himself. This exact time was very important to the Holy Roman Emperor because he was a strong believer in numerology and felt that this specific time, which formed a palindrome (1357 9, 7 5:31), was a numerical bridge, and would imbue Charles Bridge with additional strength.[4]"
Where 4 is:
"Frucht, Richard (2005). Eastern Europe : an introduction to the people, lands, and culture. 1. Santa Barbara, CA: ABC-CLIO. pp. 251. ISBN 9781576078013."
https://archive.org/details/easterneuropeint0000unse/page/25...
When you search that book on archive.org though, there are no references to "1357", "5:31", "numerology". There is a single reference to "numerical" but this relates to 1944.
So we have a paragraph in wiki, that has some very specific information, that it claims is from a book that doesn't seem to contain that info.
This is to say that 'we' don't know anything about this bridge - the sources do not check out.
I was hoping to get a little further than this. I wanted to track the primary or secondary source for this claim about the bridge build date. But I couldn't even get that far.
What should one conclude, when the detailed information being provided does not check (or should that 'Czech') out?