Location makers in Singapore. 5 mile markers. What does it mean?

 I used to hear the elders speaking of location like 5 stone marker and been puzzled what it all means. I googled and this might interest you. Its the reference point from all marker stones were measured. Before our postal codes were established, the marker stones are a way of location and identifying where u stay.
I wonder how many are still there. Anyone knows?

Taken from the internet