There is a need for providing a navigation system that enhances the freedom of settling time points to determine a destination. The system prompts a user to input only information needed for determining a target region (e.g., a region including several tourist spots or a region including several ski resorts) at a departure time. The system prompts a user to input information needed for determining a specific destination (e.g., a specific tourist spot, or a specific ski resort) halfway through the target region. Accordingly, the user need not determine a specific destination at the departure time.