La Mancha Negra

La Mancha Negra (The Black Stain) is a mysterious black substance that has oozed from roads in Caracas, Venezuela, first appearing in 1986. Since the appearance of La Mancha Negra, it has caused multiple car accidents and claimed many lives. Determining the cause of the substance has proven difficult and there are still no definitive explanations, despite almost two decades of study and millions of dollars spent identifying it.