There are no obvious traces left of Brooklyn’s grand horse racing past. Not even a plaque where any of its three storied racetracks once stood, reminding unsuspecting passersby of the famed circuit that prospered there for three decades and laid the foundation for the modern game.
Read the article:
http://www.drf.com/news/golden-era-brooklyn-racing
Don't overlook the link to a map of the three racetracks with photos.