Europe, entirely.
While Istanbul is in both Europe and Asia, the older neighborhoods of Sultanahmet and Beyoğlu are entirely part of Europe. Some of the younger parts of the city (such as Üsküdar and other suburbs) line the east bank of the Bosporus and are thus in Asia. The majority of the city, though, remains on the European side.
Europe itself is a continent and has countries inside it!
Europe IS a continent. You can't have continents inside a continent.
The District of Columbia is a city. There are neighborhoods within it, but there are no cities inside DC.
Europe is a continent composed of countries and not inside a country itself.
Not inside EU.
Streatham is a district located in southern London, England, inside the London Borough of Lambeth. The district contains smaller districts such as Streatham Hill, Streatham Vale, and Streatham Common.
The Centre Pompidou (the "inside-out building") is in the central district of Paris. It is located Rue Beaubourg, Paris 75001.
Some of the extreme northern parts of Europe are inside the Arctic Circle, which is where the North Pole is, but the majority of Europe is not in a polar region.
Italy
UEFA
I believe that the Treaty of Paris is located inside the National Archeives in Washington District of Columbia.
dry ice inside your suitcase