What would you say is drastic? In each of these regions, I've noticed different architecture, different cuisine, different accents, different social expectation

What would you say is drastic? In each of these regions, I've noticed different architecture, different cuisine, different accents, different social expectations, different political values that are widely accepted, different popular activities for leisure, different distributions of spoken languages... I haven't actual been outside of the US myself so I don't have a frame of reference for that, but different regions in the US really are quite different from my limited perspective.