‘Lost’ ancient Mexican city had as many buildings as Manhattan, laser map shows | Hacker News Reader

‘Lost’ ancient Mexican city had as many buildings as Manhattan, laser map shows

independent.co.uk

135 pointswildduck_io25 comments

as the original coverage pointed out, one of the drawbacks of lidar imaging alone is that you generally don’t get any temporal resolution.

you get “every structure that ever existed here”, basically. you still need generations of grad students and pickaxes to figure out which buildings coexisted in time and use.

the real win is that now you know where to dig, and that’s a huge deal all by itself.

Doesnt it suggest that there was some maximums size in the same general timeframe? The alternative is that they used a city like a rotating pasture or something. Genuinely curious.

Modern cities go through this all the time, growing and shrinking and growing and shrinking, just to slightly less extreme extents.

You'll very often see a popular side of town fall out of fashion, the buildings get torn down and now it's just empty lots while another side of town is built up and is now fashionable. In 20 years, the buildings fall into disrepair and since rents are so cheap back on the other side of town and empty lots abound, the other side of town is now rebuilt.

The buildings in the unfashionable part of the town don’t get torn down, it’s actually opposite — they are getting torn down in fashionable parts to make place for new ones, precisely because it is fashionable place to build. People hardly ever demolish structures to keep the lot empty — it’s an extra cost without any payback, and the old structure may be useful to some buyers, so destroying it would not only be expensive, but it would also destroy some value. If the existing structure is no good for anyone, then the cost of tearing it down is incorporated in the value of the lot, and the buyer will do it, there is no need for seller to spend money on that.

Sigh I wish you weren’t wrong but sadly you are. We demolished both of our closed buildings because the cost of not doing so (fucking transients are not free, land owners somewhere are paying for them) is higher than the cost of just demolishing the building.

Not to mention property taxes on empty buildings.

The alternative is having people buy a building, not do anything with it, and wait for the price to increase to sell it at a profit. Leading to a shortage of real estate with a ton of unused real estate.

And no, we can't just wait for the market to self-correct for empty properties being devalued due to being surrounded by empty properties: you'll just end up with empty, abandoned buildings that nobody wants to fix.

If you want incentives to make people avoid doing that, the only two methods that I can think of are property tax, or legalised squatting (with squatters having a right to stay).

One thing you see frequently in old ruins is people tearing apart old buildings for the building materials.

Historically people used to dismantle buildings quite frequently in order to reuse the building materials. Stone from the abandoned building on the other side of town is just as good as stone from the quarry 200 miles away.

> People hardly ever demolish structures to keep the lot empty

What up property tax? In my city you get reduced property tax (but not zero) if it's commercial building that is empty and unused, but I can imagine there are cities where demolishing an empty building is more cost effective than paying property tax on it every year.

Yet another reason why property tax needs to be replaced by land-value tax.

Most property value is in land, not buildings over it. Sometimes buildings carry extra premium, e.g. when zoning wouldn’t allow to build it again, but if we are talking about tearing buildings down, this is probably not the situation we are in. Thus, demolishing the building doesn’t decrease property value by much more than it costs to build it.

On the other hand, demolishing it also costs money, and with property tax rates on the order of 1% or less, it will only return in something like a decade.

All buildings require significant ongoing maintenance to avoid demolition and many have a way of mysteriously burning down when the insurance value exceeds the market value. To learn more from recent US history search “The Bronx is burning” and dig a little.

Ancient cities tended to... drift. Modern Cairo, for example, started with Memphis, which was abandoned and replaced by a Roman city called (confusingly) Babylon, which continued but declined in importance in favor of the Fustat just north of it, etc.

I was just at a site in Israel which over two thousand years was first a Hellenistic city, then a Crusader castle, and then an Arab village; at each of these steps, there was a translation sideways by about 500 meters (making their footprints non-overlapping).

I wonder if they had a high mortality rate like a lot of modern cities before the sanitary movement.

Not until the conquistadors brought the necessary bugs.

I'm fairly certain human waste had pathogens in it in the Americas even before 1492.

Maybe, but human waste is not intrinsically pathogenic. Unlike in Europe and Asia, American natives rarely had any livestock, so they didn’t have pathogens jumping from animals to humans.

If other Aztec cities are anything to go by, no. They separated clean/dirty water and made use of waste for fertiliser and dye.

http://ws.iwaponline.com/content/7/1/147

Given that Mesoamerica lacked draft animals, tropical soils tend to be poor quality, and the various cultures were probably at or around the carrying capacity of the environment, human poop was likely too valuable as fertilizer to be wasted on your drinking supply.

The headline is a bit misleading "As many buildings as Manhattan"? I see maybe 20 buildings in articles photo. Is this Manhattan in 1640 or something?

From the subhead above the picture: 'If you do the maths, all of a sudden you are talking about 40,000 building foundations up there'

The article photo is cgi reconstruction from another geological site -- not from the city described, and it says so in the caption. In fact it's in a different country altogether: Guatemala.

I think that the misleading part is that many (most) of the 40000 buildings in Manhattan are skyscrapers and the 40000 buildings in the ancient city had only 1 (or 2?) stories. In particular Manhattan has a population of 1600000 and many buildings are offices without permanent population, but that city had only 100000 habitants.

And the buildings in the ancient had much smaller footprint than 0.1 of a Manhattan city block. (Manhattan has ~2500 blocks)

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