New course

A Nitro Course is the term used to refer to an original course in the Mario Kart series that is new to the series and has never appeared before. They have appeared in every Mario Kart title. Some of them will or have reappeared in later Mario Kart games as retro courses.

Lightning Cup
NOTE: From Mario Kart DS onwards, it is the last cup of the Retro Courses.

Trivia

 * A Nitro Mario Circuit, a beach or water themed course, a snow or ice themed course, Bowser's Castle, and Rainbow Road have appeared in all of the Mario Kart games.
 * In Mario Kart: Super Circuit, the original tracks are called Super Circuit Courses to distinguish them from the tracks originated from Super Mario Kart, called Extra Courses.
 * The Triforce, Egg, Crossing, and Bell cups are the first cups to include both Nitro and Retro Courses.
 * The four worlds after World Bowser in Super Mario 3D World resemble the Nitro Cups (World Mushroom for Mushroom Cup, Flower for Flower Cup, Star for Star Cup and Crown for Special Cup).