is Monaco masculine or feminine?

ie le Monaco or la Monaco

C'est le Monaco.

Sra (aka Mme)

We do not say either le Monaco or la Monaco, this name of country has no article, as Cuba, Israel, Taiwan, Haiti, Chypre (Cyprus), Madagascar and some others. However, if it is necessary to make the agreement of an adjective or a participle, it will masculine.

Ex. Monaco que j’ai visité l’an dernier.

The word "Monaco" is masculine in French. Therefore, you would use "le Monaco" when referring to it.

Monaco is actually masculine in French, so you would say "le Monaco." When determining the gender of a noun in French, you typically need to rely on either the ending of the word, if there is a clear indication, or the noun's historical or grammatical gender. In the case of Monaco, it does not have a clear indicator in its ending, so you would have to know or look up that it is a masculine noun.