Is mapa a feminine or masculine in spanish?

You can usually tell it is a feminine because of the at the end of the Word!

Unfortunately, this is one of those exceptions to this rule. It it actually masculine. Words ending in "a" that are derived from Greek are masculine. Usually these are Words that end in "ema" or "ama", but "el mapa" also falls under this category.

Among others are el planeta, el sistema, el dia....