To get to Ecole Militaire from Gare du Nord with luggage, what is the easiest route, line 4 to Strasbourg Saint Denis then transfer to line 8, or take line 5 to Republique and transfer to line 8? Do either of these have escalators? Thanks
Either route is fine & similar but both will involve some some stairs up and down on either Metro lines 4 & 8 or 5 & 8.
If stairs will be a definite problem then another option is to take buses from Gare du Nord to Ecole Militaire. Google Maps can help with itineraries for buses.
Gare du Nord has a bus loop area on the east side of the building.