Final answer:
The location of the unsuccessful invasion of Cuba was the Bay of Pigs, where the United States attempted to overthrow Fidel Castro in 1961 but failed due to multiple miscalculations and a lack of support for the invasion force. Option a is correct.
Step-by-step explanation:
The location of an unsuccessful invasion of Cuba was a) Bay of Pigs. This event is historically significant due to the Bay of Pigs Invasion, a failed 1961 covert operation planned by the Eisenhower administration and authorized by President Kennedy. The invasion aimed to support a coup that would replace Fidel Castro's government with one more amenable to U.S. interests.
However, due to the lack of sufficient air support, a well-prepared Cuban Army, and the underestimation of Castro's popularity, the invading force of Cuban exiles was defeated, which led to a major foreign policy havoc for the United States. The aftermath of the invasion saw Castro seek military protection from the Soviet Union, further escalating Cold War tensions.