Small metallic cubes in and near London Bridge Station

I've been noticing many small metallic cubes maybe 10cm per side with a round upward facing bit jutting out of one of the sides mounted low on the walls in and outside of LBR station.

I see more and more of them around the station. Does anyone know what they are?

Sensors to monitor any movement following the demolition of the lower levels of the former office tower and dexcavations for the Shard foundations???

I think they are sensors to monitor movement caused by the Shard works too.
If you look at them they point up at a sort of lens thing near the centre top of each arch and I think it's like a fixed lazar beam to see if the walls move at all and monitor vibration.
Those arches on the railway viaduct are really old and they are already being messed with along there where part of them has been demolished.

Guidance beacons for space aliens.

That's my guess, and my friend David Icke agrees.

yeah.... I'm with phoenix on this one. Aliens, definitely.

I thought they were call commuters but aliens is just as appropriate lol

Do you think Aliens would want to land at London Bridge Station as their first port of call to SE1?