The Cloud Tops are a new area in Pokemon Genesis that is navigated with HM02 (Fly). However, instead of flying to different cities using Fly, the Cloud Tops can be accessed. Depending on where you are ion the ground and what time it is the color and weather conditions of the Cloud Tops will change. Different Legendary Pokémon can be accessed at different times. Also, Sunrise Spire can only be accessed during the morning; the same is with Sunset Spire during the night.