Which Kentucky city is known as the "horse capital of the world"?

Lexington is recognized as the "horse capital of the world" due to its prominent role in the thoroughbred horse industry. This reputation is supported by the numerous horse farms, breeding facilities, and training centers located in and around the city. The Bluegrass region, where Lexington is situated, boasts ideal conditions for raising and training horses, including rich soil and a favorable climate. Additionally, Lexington hosts several prestigious thoroughbred auctions and events, like the Kentucky Horse Park and the International Museum of the Horse, which further solidify its significance in the equine world. This extensive contribution to the horse industry and culture makes Lexington the standout answer for this question.