1. A method of generating a location based reminder by a navigation system, comprising the following steps of: creating reminder message data which include a reminder message, a primary location, a secondary location, and a validation rule where the primary location is a location associated with the reminder message, a secondary location is a location where a user conducts an activity defined by the reminder message, and the validation rule defines condition for generating the reminder message; comparing a reference location with the primary location where the reference location is a destination for a route guidance operation of the navigation system or a current vehicle and/or user position; applying the validation rule in the reminder message data to determine whether a relationship between the primary location and the reference location satisfies the condition in the validation rule for generating the reminder message; displaying the reminder message associated with the primary location when the condition defined in the validation rule is satisfied where the display includes one or more candidate secondary locations; and conducting a route guidance operation to reach a location selected by the user.