ChicagoChicago's street raisingLifting a whole downtown with hand screws is a huge job. Was raising the buildings easier than digging them out, or was something already covering the old street?In the 1850s and 1860s central Chicago was raised to a new grade. Buildings were lifted on jackscrews, and in January 1858 a four-storey, 750-ton brick building at Randolph and Dearborn went up 6 ft 2 in.
Photo: Ulisesmorales · CC BY-SA 3.0 · via Wikimedia Commons
Mud Flood · Mexico City, Mexico
Mexico City Metropolitan Cathedral
The open question
A cathedral built over a temple, both going down. Who built on top of whom?
On the record
Built in sections from 1573 to 1813 on top of the Aztec sacred precinct. The cathedral, like the city, has been sinking into the lakebed since it was built.
Sources
More from Mud Flood
ChicagoChicago's street raisingLifting a whole downtown with hand screws is a huge job. Was raising the buildings easier than digging them out, or was something already covering the old street?In the 1850s and 1860s central Chicago was raised to a new grade. Buildings were lifted on jackscrews, and in January 1858 a four-storey, 750-ton brick building at Randolph and Dearborn went up 6 ft 2 in.
ChicagoTremont House hotel liftWhy lift a big brick hotel rather than just fill in around it?In 1861 Ely, Smith and Pullman lifted the Tremont House hotel six feet to meet the new street grade.
SeattleSeattle UndergroundA whole storey of shops ended up below the street. Why build new streets a floor up instead of on the old ones?After the 1889 fire, Pioneer Square's streets were raised from several feet to a full storey. The old sidewalks and shopfronts are still down there, lit by glass vault lights. The city condemned the Underground in 1907.
SeattlePioneer Building, SeattleIf the old ground floor is underground, which floor was really the first one?Built in Pioneer Square after the 1889 fire; Bill Speidel's Underground Tour has run from it since 1965.