A "Garden Path" sentence is a grammatically correct sentence that initially leads readers to interpret it in one way, only to require a reevaluation for proper understanding. This phenomenon occurs because the structure of the sentence misleads the reader, creating confusion before the true meaning is revealed. For example, the sentence "The horse raced past the barn fell" can mislead readers into thinking it describes a horse racing. However, the correct interpretation is that a horse, which has been raced, is the subject of the sentence. Garden Path sentences highlight the complexities of language processing and comprehension.