'Accidental' unearthing of papal palace under Rome

[Imperial Dave]

https://www.independent.co.uk/news/science/archaeology/pope-palace-rome-secret-reveal-b2747785.html

Careless...

[Jim Webster]

Moved back home when they no longer needed the defensive wall 

[Nick Harbud]

I imagine this is a big problem when building in Rome.  I mean, practically anywhere you put a spade in the ground, you are bound to hit the foundations of something from a previous age.

[Imperial Dave]

Inconsiderate builders...