Line 1 of the Paris Métro has 25 stations.
Opened in 1900 for the Paris Exposition, Line 1 originally ran between Porte Maillot and Porte de Vincennes. It crossed the city from west to east along major routes including the Champs-Élysées, the Louvre area, Hôtel de Ville and the Bastille.
The line grew through several extensions. It reached Château de Vincennes in 1934 and was extended westward to La Défense in 1992. That modern extension explains why older diagrams or historical accounts may show a shorter route and fewer stations.
Line 1 is also notable for its unusually high traffic and for becoming Paris's first fully automated Métro line. Automation was introduced in stages and completed in 2012, allowing trains to run without drivers while stations continued operating normally.