:up: ...or indeed 'Mexico City' and several others. They usually (always?) have the word City capitalized to distinguish them from some other organizational entity: New York City is distinct from the state of New York, Mexico City is distinct from the country Mexico...
There is no reason to. It's just called Tehran. You might qualify it in advance by saying "the city of Tehran" or "the city, Tehran" depending on context. However, as usual, we would need a complete sentence to work with.
Does this contrast with some other part of Tehran? If not, there really is no need to- Tehran/Paris/Berlin, etc, don't require such qualification to us.
Does this contrast with some other part of Tehran? If not, there really is no need to- Tehran/Paris/Berlin, etc, don't require such qualification to us.
Who's your audience? Many will know the city and not the province, so it would be unnecessary. However, I would still use the city of Tehran if you needed to make the distinction, but I would be more likely to make the distinction for the province rather than the city.
As an example, if someone says Washington, I assume they are referring to Washington DC, not the State of Washington, simply because we talk far more about the city than the state.