Espíritu Santo fort was a Spanish fortress that existed in the region of Nacimiento on the left bank of the Bio Bio River immediately below its confluence with the Tavolevo River .
Espíritu Santo fort was a Spanish fortress that existed in what is now the commune of Nacimiento , Bio-Bio Province , Bio-Bio Region of Chile . 
 It was on the left bank of the Bio Bio River immediately below its confluence with the Tavolevo River .