Porton Down, Salisbury, Amesbury, next? (England)
This is the place for VX agents (so-called novichok)

porton down

Holidays in England?...

Unfortunately this center of production of toxic agents is close from famous touristic sites. In the past, contaminations were reported not only in Wiltshire, but also in Dorset, Ross and Cromarty, etc. Spies, politicians, professional military staff, mafiosi take risks; but it is not normal that Foreign people might be at risk.

Info for beginners:
https://en.wikipedia.org/wiki/Porton_Down

Intermediate:
Find yourself Compendium of Chemical Warfare Agents, Handbook of chemical and biological warfare agents and other more detailed cooking manuals.

Advanced:
Theresa May and Boris Johnson suggested enough hints to Daesh, Al-Qaeda, etc.