This article offers a photo journey to 15 of the world's smallest regions. Some are independent countries, while others are territories, but they're all under 30 square miles.
The list includes:
the world's smallest region, at .17 square miles (hint: it's in Europe);
the world's smallest island nation, at 8 square miles
a one square mile nation state (also in Europe and has a monarch)
the world's oldest surviving sovereign state (Europe again)
and what has to be one the world's least populous territories at less than 50 people (an island and British Territory, think mutiny).