This bridge does not actually appear to be made of chain, nor is it made of rocks. If it were, driving cars across it might be a little bit tough.
I actually have several photographs of it, and in one, (not this one) you can see a car on it, although cars are no longer allowed on it. Instead it is used for biking and walking.
I Googled “chain bridge’ and came up with hundreds of different bridges called ‘Chain Bridge’, as well as several places called ‘Chain’ that have bridges.
This one is located on the old route 66 in St. Louis, Missouri, here in the USA.

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