Everything tagged: Stone marker

The Mansfield Road facing side reads BO 23 and the opposite side WD 2.

Anybody with knowledge of the meaning? 

Hi there,

I found there is a white cube of rock at the summit, past the trigonomatrical station, right besides the fence.

I couldn't find any marks on it.   Does anybody know whether it is a natural rock formation or artificial?

Best Regards,

T