I am using this design
with the only exception that C2 is 150nF to change timing slightly. When I plug in the circuit and attach an LED across GND and pin 3 output the LED is static on. However, on closer inspection with a multimeter frequency setting it says that it is 700Hz. Why though? This should provide a frequency of around 1Hz with these resistor and capacitors. I am using an LM555CN chip.