trains on line 10 are serviced by the depots at auteuil, which are connected to the tracks of the terminus "porte d'auteuil". these depots are entirely underground; other than tunnels, an escalator located on the sidewalk of the "avenue du géneral-sarrail" provides access. the depots are connected to line 9 as well, however line 9 has not used these depots since the opening of those at "boulogne" connected to "pont de sèvres".