Lumiose City is the city where the Kalos Pokémon League is held in Pokémon the Series: XY.
The Kalos League takes place at the Lumiose Conference in Lumiose City, the large central metropolis of the Kalos region. Ash reaches the final of the conference, where he faces Alain in a battle between two powerful trainers.
Lumiose City is also home to major landmarks seen throughout the XY story, including Prism Tower and the Lumiose Gym. Its central position makes it one of the most important locations in the Kalos arc.
The city should not be confused with the Kalos League’s conference name. “Lumiose Conference” refers to the tournament, while Lumiose City is the location. Laverre City and Anistar City host other Kalos Gyms, and Victory Road is a route rather than a city.