We would not have seen the circles

 in the pavement if it had not been raining.  The guidebook gave us directions to an old pharmacy (apothecary) which does not exist now.  Look for circles in the pavement it said and told us how many meters away from the pharmacy they were. 
Husband and I must have looked very strange as we walked all over the square, seemingly looking at our feet.  But we finally found the circles which indicated where the pharmacy - in very old times- used to crush their ingredients. 
A few days later, on a sunny day, we were walking back through the area and the circles could hardly be seen.