Absolute lowest altitude you can fly (legally)

In Canada it's the same, with the proviso attached "except
when taking off or landing." It would be impossible to land or take off
at most airports if we had to stay 500' away from any person,
structure, vehicle or vessel.
Low flying kills people.

Same thing in France. The minimum height above ground was raised from
150 to 500ft a few years ago because of deadly accidents.
But this minimum is not valid everywhere. Especially above cities where
a minimum height of 1600, 3200 or 5000ft is mandatory, depending on the
size of the city. (You find this information on the charts.)

Thierry,
PPL,
http://www.airpictures.net
http://flyinfrance.free.fr