Where is the best place to tour if a person is interested in medicinal herbs? I'm particularly interested in places where the herbs are grown, harvested, and processed at one location or region. Thanks!
Amsterdam if what you actually mean is herbs to smoke, otherwise a purveyor of traditional medicine in whatever city you go to.
If maximum vagueness in the question could be 100, I'm afraid that your question is high in the 90s.
Aboca museum in Sansepolcro, Italy
Which country are you going to be in? There are dozens in the UK alone including Jekka's Herb Farm (Chelsea Flower Show gold medalist several times over), Chelsea Psychic Garden, The Geffrye Museum in London and Alnwick Castle (known as the poison garden).
Chelsea Physic Garden is a good suggestion. We really enjoyed our visit there.
When in Switzerland I found it interesting that the pharmacies dispense herbal remedies for many ailments. Ricola has a demonstration herb garden Innthe village of Kandersteg.
We went on a medicinal herb walk with a naturalist in the Dolomites.
Nepal...as I visited an entirely herbal pharmacy with hundreds of herbs to select from for about every known disease.