Text: A constant cycle of building, decay, collapse, and rebuilding plus the occasional catastrophic fire gave the Old Town its characteristic irregular layout and chimney-strewn skyline.
Entailment: Old Town's characteristic chimney-strewn skyline and irregular layout come from a constant cycle of building, decay, collapse, and rebuilding, along with the occasional catastrophic fire.
Contradiction: Old Town's lack of catastrophes led to a regular layout and clean, distinct skyline.