Modern is tough because it isn’t hundreds of years ago.
Around me, The High Bridge between Bronx and Manhattan was built pre Civil War and abandoned for decades and still standing (and now is use again). The Hell Gate Bridge was built by the NY Central Railroad and will probably outlast the US.
Lots of 19th century infrastructure will be around for centuries, if you look at the the path of the Erie and Lackawanna railroad routes, many bridges and other infrastructure will be standing hundreds of years from now. Lots of interstate infrastructure will function for hundreds of years in rural areas with low traffic, well beyond their engineered lifespan.
Stone is the most durable material and structures are overbuilt. Steel is much cheaper but requires maintenance.
It seems like that's an impossibility, since you would need to find something in the current era that has been abandoned, rather than decommissioned...
There are a few examples that might fit, some earthworks, (tunnels, breakwaters, dams) and navigation markers come to mind (costal, but we also put retro reflectors on the moon).
Yeah, I was thinking about Vauban's fortifications, but if any of those had been abandoned, it's specifically because they would have been mostly useless after WW1 (= non-functional).
Hmm, any Vauban-like fortifications in Ukraine that would have suddenly found a new use since 2014 ?
> Can you point to an engineering feat in modern times which is still functional after hundreds of years of neglect?
Why would anyone build something only to neglect it? If one of the requirements was "it shall work for 500 years and never be maintained", then I'm sure you could get plenty of things designed and built for that requirement. It's just that it's a lot more expensive and not particularly useful, so nobody bothers.
> the lack of respect in your position is certain.
Pointing out there are other possibilities isn't a lack of respect. If you believe A or B could have happened, you see someone say B happened, it is fair to say that A might have happened as well, that doesn't mean you believe B couldn't have happened.
> Can you point to an engineering feat in modern times which is still functional after hundreds of years of neglect?
Off the top of my head:
1. Various aqueduct systems constructed by the Roman Empire are still in use today.
2. Persian qalats.
3. The Grand Canal in China.
4. Roman Roads
5. Hawaiian aquaculture systems
6. Aboriginal Australian fish traps
Monumental architecture (e.g. the Pyramids) would make the list substantially longer.
> Even if academia is swinging to a "too respectful" position
The issue isn’t that they are attributing accomplishments to these civilizations, but instead that they are attributing these accomplishments to a way of knowing that is purportedly superior to that of the Europeans, which is just farcical when you consider that every modern technology has either been invented or scaled based on European models of thinking (e.g. the scientific method, mass production, free market capitalism, etc.)
Like I said, this is mostly just a product of Mexican and American humanities departments being populated by people with an axe to grind; there aren’t any STEM graduates in South America concerned with the mystical knowledge that their ancestors are purported to have possessed.
I am not sure of their operational status today, but in Medieval Western Europe, it was Carmelite communities who built aqueducts; even as they struggled to reform themselves during the Counterreformation, religious communities were undertaking large-scale engineering projects, because they controlled enough labor workforce, as well as technology and supply chains, to make that happen.
I would be unsurprised if the Carmelite Orders likewise invested significant maintenance in the old Roman construction, and learned from it as well.
Hundreds of years, whether of neglect or not, means that it wasn't "in modern times". And, in modern times, hundreds of years of neglect is hard to come by. Either it's maintained, or it's torn down, because we haven't had civilization-ending catastrophies in modern times. So I would not expect to be able to show you many examples, because the pool of candidates is so small.
Even if academia is swinging to a "too respectful" position (which I would dispute), the lack of respect in your position is certain.