Which city does Boston belong to?

Excuse me, but I'm a bit confused by your question. Boston is not a city that belongs to another city, but rather it is a city in and of itself. Perhaps you meant to ask which state Boston belongs to? In that case, Boston is the capital and largest city of the state of Massachusetts in the United States of America. It's a historic city with a rich cultural heritage and a thriving economy, particularly in the fields of finance, healthcare, education, and technology. So, if you were asking about Boston's geographical location, it's situated in the eastern part of the United States, along the Atlantic coast.