World’s FairsFound, not built?
HypothesesThe ground came up: buried floors are everywhere

Hypothesis #4 of 20

The ground came up: buried floors are everywhere

Strong110 supporting entriesUpdated (was strong 44)

Strength is how much of our gathered material lines up with the pattern. It is not the odds that the idea is true.

The working idea

Buried ground floors, stairs that go down to a door, raised streets and dug-out temples appear in 35 countries in our collection, from Seattle to Rome to Edfu. Common sense says ground doesn't rise metres in a few centuries without something bringing it. The documented causes vary (river silt, drifting sand, volcanic ash, rubble, deliberate street raising), but the result is the same: older cities sit under newer ones far more often than most people picture. The open possibility is that some of the raising on record was the cleanup of a deposit rather than a choice.

Strongest examples

Seattle UndergroundOld sidewalks and shopfronts still down there, lit by vault lights.Luxor Temple and the mosque on topA working mosque whose door is high above the cleared temple floor.Pantheon steps, RomeVisitors walked down to the portico until the 1600s.Grand Central: arched windows at the debris lineGrand Central 1913: arched windows at or partly below the debris line.

The evidence

Buried, raised, sunk or dug-out places in the Mud Flood section (44 before + 66 from the second batch)

110 in 35 countries (top: Italy 17, United States 15, United Kingdom 10, Egypt 8, Mexico 7, Turkey 6, France 4, Greece 4)

110 entries

Round-2 rows by kind

sand 19, lost 14, sunk 14, volcanic 8, raised 7, sea 4

Each second-batch line is quoted from its source and keeps the cause the source names (volcano, river, sand, storm, later building).

Depths on record

Pantheon 1.3 m; Baptistery of Neon about 3 m; Temple of Hadrian 5 m; Pompeii 4–6 m; Temple of Edfu 12 m; Herculaneum about 20 m; Galveston raised up to 17 ft; Chicago building lifted 6 ft 2 in

8 entries

US street raisings, all between the 1850s and 1928

6 cities/projects

6 entries

Found by accident

8

8 entries

Tunnels with no clear builder

3 small Western towns

3 entries

Photo clues of windows at or below grade, or dig-outs

10 (7 below-grade-windows, 3 dig-out)

10 entries

Raised ground in the second batch

7: Ephesus (street raised by Emperor Arcadius), Cairo IL (buildings designed for a higher street), New York African Burial Ground (grade raised with landfill in the late 1790s), Park Glienicke, Port Adelaide (raised about 9 ft with dredged mud and silt), Schenectady (railroad grade raised; station 1908), St. Johns River Light (grade raised about 7 ft)

7 entries

Open questions

  • What is the fill under the raised US streets made of, and has it been tested?
  • Why were raised streets carried out within a few decades of each other in cities as far apart as Chicago, Seattle, Galveston and Atlanta?
  • How many downtown 'basements' have finished shopfronts, vault lights or doors?

What would support it

  • Fill under raised streets that is a uniform silt or clay rather than city rubble and dredged sand.
  • Buried storeys with finished facades in cities with no raising on record.

What would rule it out

  • Cores showing fill that matches the recorded source (Galveston channel sand, Seattle regrade spoil).
  • Each buried site having a local, dated cause on record. Most of the 110 do, and the second batch quotes the cause in the line (ash, sand, silt, landfill, later building). The pattern is real; the single cause is what is open.

Selection bias

Medium: sites were collected because they are buried.

The rating counts how much of our gathered material lines up with the pattern. It is not a probability that the hypothesis is true, and every count is limited by which buildings were picked for the app (see 'selectionBias' on each card).

Next hypothesis

Strong57 entries#5Built in two years, gone in one: the 'temporary' palacesEvery fair palace in our records is said to have gone up in three years or less, while permanent capitols and cathedrals of the same era took 8 to 24 years. Then most of the palaces were taken down or burned within months or a few years of closing. Common sense asks why anyone would spend that much effort on buildings meant to last one season, and why the 'temporary' ones went up so much faster than the permanent ones. One possibility is that some fair sites re-used or cleared existing structures, and the fair was the story that went with the clearance.

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