360CityArena: A Realistic Virtual Urban Navigation Benchmark for Embodied Agents

We present 360CityArena, a benchmark for evaluating theurban exploration capabilities of Embodied Agents within a photorealis-tic environment constructed from 360° videos. Existing outdoor bench-marks either lack sufficient photorealism or complexity, resulting in aconsiderable gap from real-world urban environments. 360CityArena isbuilt on a realistic reconstruction of the Akihabara district in Tokyo,Japan, using 602 360° video segments covering 85 streets, and consistsof 175 meticulously human-crafted tasks. It encompasses three task cat-egories: Environment Understanding, Path Reasoning, and Spatial Rea-soning, covering fundamental abilities required for urban exploration,such as localization, landmark search, path planning, and relational spa-tial reasoning, thereby enabling comprehensive evaluation in realisticurban scenes. Our evaluation using state-of-the-art LMM-based agentsshows that even the strongest model, Gemini-2.5 Flash, performs far be-low human level (human: 77.3% vs. Gemini-2.5 Flash: 17.1%), revealingsubstantial challenges that remain in city-scale embodied navigation andreasoning. 360CityArena provides a necessary and challenging testbed forphotorealistic urban-district navigation and spatial reasoning.