Cueva de la Quebrada del Toro  The Cueva de la Quebrada del Toro is a cave in the Sierra de Falcón in Falcón State, Venezuela. It is an active river cave, through which flows the largest known underground watercourse in Venezuela. It is protected as the Cueva de la Quebrada del Toro National Park. Like the Cueva del Guácharo National Park, it has a population of oil-birds (steatornis caripensis).