The mark consists of a circle which has been divided into a white half and a black half horizontally. Within each half of the bisected circle is an image of a grey Eiffel Tower, properly oriented in the upper, white half, and upside-down in the lower, black half. In the upper, white half, there is a man in black and white carrying a globe, with the water on the globe in blue and the land mass on the globe in green. In the lower, black half, there is a magnifying glass with a blue handle extending outside the circle. In the lens of the magnifying glass is a photograph of a train and station from the Paris underground metro system. The train in the photograph is off-white and teal and on grey train tracks, and the station is mostly white with neon orange, neon green, and neon pink colored graffiti in the background. Diagonally across the center of the mark is the phrase "Paris Underground / Paris Souterrain", with the phrase in white while in the lower half of the circle and grey in the upper half of the circle.