Zero in a basic RC high pass filter
For a low-pass or a high-pass simple RC filter, there is always a pole and always a zero. For the low-pass the zero is at infinity i.e. infinite frequency. For high pass, it is at zero frequency (aka DC).


  But If I simply look at this circuit I would say that there is one
  pole and no zero


If I look at it I see a DC blocking capacitor hence the output cannot have DC content hence there is a zero at DC (0 hertz).