Dragon Quest
Kol is typically the 3rd town the hero visits. It does not contain any essential items for completing the game. The Fairy Flute is hidden 4 steps south of the fountain and is useful for defeating the Golem outside Mercado.
Dragon Quest II
As is the case with most of the towns/villages in Alefgard, Kol is not accessible in Dragon Quest II. Its location on the world map is covered with forest.
Dragon Quest III
Kol contains the item shop which sells the Sword of Kings, which is the hero's strongest weapon in the original Dragon Quest III (but not in remakes). The sword is for sale after selling Oricon to the Zipangu shopkeeper and re-entering the village.