When I first saw these I thought they were old street lights but if you look at the second picture it is apparent that one is much smaller than the other two.
The small one is probably just a streetlight but the other is much taller and of larger diameter.
There's another (on it's own) a bit further up the road.
Are they just sewer gas lamps? If they are, they're quite close together and very close to an ordinary lamp.
Big one and little one here
Large one on its own