I have a few since I'm a historian:

The revolutions of 1848 Europe, particularly Berlin or Paris. The atmosphere in that year was confusing, conflicting, and explosive. People wanted generally better lives, and put their own on the line to see it happen in numbers that shock us today.

The fall of the T'ang dynasty and the early Song dynasty. I'd love to see if the Naito Hypothesis holds up as a viewer of that time and space.

The Atlantic Revolutions between 1770s to 1800. So American, Haitian, French, etc. The birth of nationhood (in Europe), a new consciousness found its footing, and what it meant to have liberty, to be human, and to be unfree were changing.

And Japan in the 1930's. How fascism developed in the country. It's a question that's big in Japanese history, and not so clear today.