## 1 Introduction  
Pedestrian navigation we use in daily life could provide accurate navigation instructions and support various exploratory activities. Well-designed navigation could encourage people to go outside for outdoor exploration [1] and help the local tourism industry and commerce flourish [2; 3; 4; 5]. Nowadays, research on pedestrian navigation has become increasingly popular in different disciplines. With the development of technology, the user interface of pedestrian navigation is constantly evolving [6]. In particular, immersive technology such as augmented and mixed reality can display virtual navigation information on a real-world interface [7; 8; 9; 10]. These technologies have constantly changed how pedestrians learn and interact with location-based information, especially in urban exploratory activities. For instance, some studies and applications have applied augmented reality location-based games and exploratory navigation for entertainment, tourism, and urban exploration [11; 12; 13; 14; 15; 16; 17] to enhance user experience. However, though mobile augmented and mixed-reality technologies are gradually coming out of the laboratory and into our lives, they have not yet been embedded in practical applications. Moreover, as people have become accustomed to accessing information via mobile devices from the Internet, the interactions between humans and their digital machines have become more diverse and complicated. Therefore, the user-interface design and navigation system's interaction might affect pedestrians' experience from different layers. Some research has focused on technology to resolve the challenges in a physical sense,and physiological safety, such as GPS technology, route planning method, and navigation instruction visualization; in contrast, the study of mental satisfaction during navigation is not rich [18]. For example, an increasing number of studies on human-computer interaction (HCI) have started to pay attention to the fundamental usability and preferences of user-interface designs for augmented and mixed-reality navigation [19; 20; 21; 22; 23; 24]. However, in [6], [PERSON] et al. suggested that mobile maps not only need to be efficient but also should be affective and emotionally pleasing to produce a positive user experience. In recent years, research on exploratory navigation has arisen [25; 26; 14; 27; 16]. These studies and technologies are applied in entertainment, tourism, and other location-based services, inspiring HCI research on navigation systems. Compared with the conventional interfaces of navigation applications, augmented reality navigation can reduce the cognitive deviation between the 2D map interface and the locations in the physical world. It can also display point-of-interest information as virtual marks for pedestrians to find [28; 29; 30]. These advantages assist pedestrians not only in orienting and navigating, but also by helping them to explore the surrounding points of interest. However, although augmented technology provides a good navigation guidance visualization experience, some challenges remain. For instance, sometimes, there is an inability to identify off-screen POIs accurately, so there is a failure to grasp the holistic spatial information. In addition, the improper visualization of the overloaded point-of-interest information might also damage the experience and satisfaction of pedestrians in exploratory navigation. Therefore, HCI researchers must investigate how to comprehensively enhance pedestrian mental satisfaction through a suitable and comfortable navigation interface. Based on the above challenges, in this work, we propose a mixed-reality 3D minimap as a part of the navigation interface through the mobile head-mounted display to support urban exploratory navigation. We hope the proposed map interface will provide pedestrians with a holistic view of spatial and environmental information and increase interactivity with the virtual contents rather than just displaying the virtual marks through hand-held augmented reality navigation.