The American embassy

Hello Teachers,
(I am describing where I live.)

Also, down the street from our house there is the/an American embassy.

Which one is right? "The" or "an"? There is only one American embassy in the country, so "the" is recommended according to the rules. On the other hand, "an" sounds better to me. What kind of embassy = An American one.

(Or I could say, "The American embassy is down the street . . ." but I want to see how it works in my original example.)

Thank you!!