The correct spelling is Guant�namo, so the emphasis is on the 2nd a. Guant�namo Bay is a US base in Cuba - of all places. The USA leased the land in 1903, and despite efforts to remove them by the Castro government, such as cutting off the water supply, they are still there, albeit in fewer numbers than in the early 1960s.
Full marks to sgs for a timely mix of Spanish language and Cuban history. A person who comes from the town of Guant�namo is a Guantanamero in the masculine, or a Guantanamera in a feminine - in each case, the stress fall on the "e". Thus, the name of a reasonably famous song, which is very beautiful when sung in its true form, rather than in the "touristy" versions one hears all too often.