Photo: Xavier Quetzalcoatl Contreras Castillo · CC BY-SA 3.0 · via Wikimedia Commons
Mud Flood · Mexico City, Mexico
Palacio de Bellas Artes
The open question
A palace sinking four metres in a century. Did older buildings go the same way, and get called 'basements'?
On the record
Since construction began in 1904, the theatre (opened 1934) has sunk some four metres into the soft soil.

