What are some structures today that you think will become "anceint" structures in the future

I watched a show that asked this question. The undisputed champ was ~~Hoover damn~~ Mt. Rushmore with an estimated expected life of hundreds of thousands of years.

EDIT: It was Mt Rushmore not Hoover Dam.

Hoover Dam is also expected to last a long time. The forces on the structure are mainly compression and it isn't a seismically active area. The big question is whether the electricity generating turbines would fail open or shut.
- What about servicing those turbines so they don't fail at all? "This dam powers our city since 4000 years." Sounds nice and Star Trek-ish doesn't it?
- For sure, but Rushmore and the Pyramids have basically no time limit. The Pyramids might get buried by the sands though.
Do you remember the name of the show?
- No. It was one of those History Channel (maybe TLC or Discovery) thought experiment shows like "what would happen if all humans disappeared". The dogs was a hard watch. I didn't need to think about doggos starving to death at home as they waited for their humans to return. Strong Futurama's Jurassic Bark feels.
- all of the Planet of the Apes movies had this.
- The View.

Hoover and three gorges dams. That much cement will be noticable for a long time.

"Low cost" levys and break waters, since those just use large cut rock dumped in the water.

A lot of modern engineering uses a more advanced type of cement than the ones ancient people used.
It's chemically stable so it doesn't react with the environment and has a predictable lifespan.
A side effect of this is that it predictably only reliably lasts about 100 years.
Older cement could react with the environment, which meant sometimes it broke really fast, but also sometimes it is able to heal small cracks and last indefinitely, if it doesn't get a mold outbreak.

The pyramids are basically a big pile of rocks, so that isn't going anywhere.

So for modern buildings, you'll want to look for structures made from cement intended to last a very long time with low maintenance near water, like the biggest dams, or things made out of cut rock, like low cost commercial port break waters.

We just don't make as many structures out of raw rock or crappy cement anymore, so it's not as likely for a lot of buildings to survive.
On the flip side, we do have a lot more buildings, so they'll probably find random elementary schools in Nevada in 4k years.

It's worth noting that steel reinforcements drastically reduce the possible lifetime of a concrete structure. It'll eventually rust which causes it to expand inside the concrete which will cause the concrete to crumble.
Being pedantic but it’s concrete not cement. Cement is one of multiple ingredients of concrete. It’s a binder.
- That's fair. I was thinking about the active part that causes the difference in lifespan while typing. :)

Large Hadron Collider could be an interesting candidate. It’s not very visible, but it’s unique, gigantic, and insulated from damage

If abandoned I doubt it will remain insulated indefinitely, it would likely be underwater. A lot of random bits would survive though.
- It's about 200m below the surface, but the surface is about 400m above sea level, so I don't think flooding is a major risk.
  
  Cern has a risk assessment here :
  
  Although the LHC is running through the territory of a few municipalities, only one of them had as much as three floodings between 1983 and 2004, the remaining ones even less than three [38]. As there have been no reported consequences for the LHC tunnel, a natural cause for flooding will not be the crucial factor for the determination of the probability of occurrence.
  
  Climate change might change that but it doesn't seem like long term flooding is a major risk even if abandoned.

modern structures are far too fragile to last very long without continued maintenance so likely nothing.

This is because we intentionally build them the way we do because we expect to replace most of them in a relatively short period of time so we use the least amount of materials and the materials we use do things like corrode and rust unlike the giant rocks that ancient societies used in the structures that stuck around. A lot of our structures are also near waterways, which increases the decay.

We will still leave behind a lot of earthen structures like highway overpass ramps, stuff cut into mountains, and the giant holes from strip mining.
- archeologists of the future examining an on-ramp remnant: “We believe this was used for some sort of religious purpose, likely to bring people to a higher elevation to get them closer to the divine.”
True, however most of the materials they are made of can't be maid naturally so even if our cities are taken back by nature, advanced civilizations would still be able to figure out that there was something built here from the atomic residues that these materials leave behind.
- That may be the case but seems pretty unlikely. Sure there are a lot of manufactured components in modern buildings but they are mostly comprised of volatile elements that may cause isolated and wholly unrecognizable pockets of confusion rather than an understandable record. I don’t think they’d be noticeable among the other natural remnants, especially if we get the point that, say, NYC was reduced to a blip in an entire geological record.
  
  For all we know, there were “intelligent” dinosaurs that had an entire civilization that got crushed into one little strata that had a little too much Iron or maybe Saurium.
  
  It’s of course all based on the timescale. Horizon Zero Dawn does a good job; if memory serves it’s only a few hundred years so it made sense remnants of “modern” America were present—if that game was set, say, in 10,000 years (when love is illegal) it’d be much less believable that the USAF Academy chapel was still standing.
  
  If we’re talking on the timescale of millennia then it becomes much less likely anything we’ve currently created would leave any sort of mark, except maybe some radioactive patches here and there (in which case the song Radioactivity will automatically play so that will keep people safe [we should all thank Think of Wyverns for their service]).

Stone memorials - like the Lincoln, Jefferson, Vietnam, or WWII memorials in Washington D.C.

Park system buildings that are made out of stone.

Missle silos.

I'd say a few of our largest Cathedrals are good candidates. The Jesus statue in Rio naturally. The problem really is that it's only ceremonial/ornamental buildings that have any likelihood of standing through the rapid modernization of our cities and most we've built in recent years aren't very robust nor interesting since we consider expensive, large, massive ornamental structures a waste of tax payer money these days.

The Bass Pro Shops pyramid instantly comes to mind.

Define ancient Many large building will last for millenia. If we still use roman theatre and medieval palace/church we may keep using large building (provided we can keep the lift working)

Why is the typo quoted though?

OP might not know that Lemmy allows editing the title.

Onkalo spent nuclear fuel repository in Finland ought to make the list if CERN is allowable.

Iconic Manhattan skyscrapers - Empire State Building for sure. Regardless of societal changes it will become a protected cultural heritage.

Palace of the Parliament in Bucharest - it's just too big. Nobody likes it but but demolishing would be too expensive. I expect this situation to continue forever.

Eiffel Tower - another iconic landmark. And very simple to keep maintained as long as you have enough steel. If it gets destroyed for whatever reason, Parisians will rebuild it.

Sea reclamation structures in the Netherlands - Especially those built during 20th century. Even if active mechanisms fall out of use, it will remain around as a ruin of ancient civilization for a long time

Parisians will rebuild it.

Reminded me of this gif:
If we get a sea level rise of 23 meters the first floor of those skyscrapers will be underwater, which will drastically shorten their lifespan
The Bucharest palace looks architecturally appealing to me. Anyone know of any other examples of behemoth's like this?

I can see it being hollowed out and converted into a huge shopping mall at some point.

A process, instead of a thing:

political-election based rule, selecting for narcissism/machiavellianism/sociopathy-psychopathy's rule.

IF humankind survives this-century's The Great Filter, in-which Kahneman System-1 ( "Thinking Fast & Slow", the most-important psychology book in the world, now ) fights to break System-2/considered-reasoning from having any authority,

and is winning.

ALL the ideology/prejudice highjackings-of-countries happening everywhere throughout our world, these days, are just "makeup" on the underlying animal-reaction-mechanism fighting-off considered-reasoning from this world.

So, in order to survive, humankind requires to break System-1 from authority, globally.

ALL ideology/prejudice addiction-styles, left, right, religious, anti-theist, ALL of them, have to be broken from rule, XOR humankind force-extinguishes itself, this-century.

It's incredibly elegant, actually:

I believe that all worlds who cross the threshold heading toward their own Industrial Revolution sequence ( so I'm talking about the Roman Empire's crossing of the threshold ), can have the same ScientificallyTestablePredictions/"prophecies" dropped into them,

about how there will be #ClimatePunctuation and #SpeciesWideCivilWar & #GlobalFoodWebCollapse .. and all-3 of these predictions are in the Christian Bible's Revelations-book, you can drop these same predictions into ALL worlds going into their remaining-toddler-unconscious-mind while having planet-crushing-industry & planet-destroying-military .. and the result will consistently be the same: toddlers aren't responsible, and TANTRUM/POGROM instead of growing-up.

Which is exactly what humankind's going to be doing for about 6 decades, once things blow-up, in about 1 decade.

I don't expect much in the way of survival of humankind, at the end of this century.

If any.

However, Universe/consequences/karma, whatever one wants to label the force-of-nature, isn't going to cater-to our toddler-mind's god-complex, and Universe is going to corner us into force-enduring consequences until either we're extinguished, xor our remnant is grown-up in nature, no-longer toddler-nature.

All the 600+ mass-shootings in the US last-year, were narcissism's lashing-out & tantruming/pogroming others, to "get even" with not being catered-to.

Our entire-species is in the process of setting-up that, at planet-scale.

Russia & Israel are committing "mass shooting" against other nations, for their genocidal narcissism...

US Civil War Part2's going to be an internal demonstration of it, within 1 decade.

Everywhere.

All at once.

Our species's epitaph.

Tantrum/pogrom was the best we could do: growing-up was "too hard" and unendurable.

That's what we're carving in Universe's eye, now.

Its basis is wrong-sorting, preferring narcissism/machiavellianism/sociopathy-psychopathy for authority, suppressing responsibility & hard-lessons-learned from authority.

_ /\ _

bro what