to their line (before the merger with the old line 14 the extension towards Châtillon – Montrouge and the creation of a new workshop). In preparation for the ascent of the Montmartre hill, the line veers sharply north in two curves of radius, putting the tunnel under Rue Notre-Dame-de-Lorette. There it climbs on a 4 per cent slope until the next station, Saint-Georges, which is divided by a pedestrian access way. Line 12 climbs on towards Pigalle station, where the Moulin Rouge is situated, and it intersects with and runs under Line 2 and passes under a sewer. Between Abbesses and Lamarck-Caulaincourt stations, the tunnel crosses Montmartre at a maximum depth of , close to the Basilica of the Sacré Cœur, making Line 12 the network's deepest. At Lamarck-Caulaincourt station, the line reaches its highest point, after which it makes a 4 per cent descent towards Jules-Joffrin station, situated under Rue Ordener, then to Marcadet-Poissoniers station, where the line again crosses Line 4. The tunnel runs underneath the railways departing from Gare du Nord, then slants northwards in a radius curve into Marx Dormoy station, in the Goutte d'Or neighbourhood. The line continues down a slope of 2.6 per cent, with new bends, before arriving at Porte de la Chapelle station, on the northern edge of Paris. This station was previously the northern terminus and has three lines with platforms, leading into a four-tunnel depot. Beyond the depot, a new tunnel was constructed for the first phase of the extension towards Aubervillers, passing underneath the ring road, and exiting the northern fringe of Paris for the first time. After an eastward curvature, the line arrives at Aubervillers - Front Populaire, the first modern station of Line 12. The new station is situated at the edge of Saint-Denis and Aubervilliers, and is a traditional 2-track layout with platforms on either side of the track. After this, the line continues via Aimé Césaire to Mairie d'Aubervilliers(From :fr:Ligne 12 du métro de Paris). Stations Line 12 consists of 31 stations, including 12 with connections to 9 other metro lines and one RER line, two Transilien networks and two national railway stations. Design features Because of the competition with the CMP, the Nord-Sud company paid a special attention to design elements. One of the notable elements is the Saint-Lazare station in which architect Lucien Bechmann designed a rotunda for the tickets and transfer room.