该岛为内外套叠的双破火山口（double-caldera）地形，火山仍属活动状态；最近一次有记录的喷发为 1785 年（原文：1785）。那次喷发使救援船因降灰被迫撤退，并造成 140 名村民（原文：140）因灼伤与溺毙死亡；内火山口 Maruyama 由岩浆与火山碎屑堆积形成。江户时代（1603–1868；原文：1603-1868）的流放数量呈现风险梯度：Miyakejima 2,300 人（原文：2,300），Hachijojima 1,865 人（原文：1,865），Aogashima 仅 6 人（原文：six）。
旅游承载量接近零：仅两个聚落 Nishigo 与 Yasundogo，缺乏 hotels、cafes、convenience stores；餐食仰赖 minshuku，访客常需自备补给（例如 2 L 瓶装水；原文：two-liter bottles）并以步行探索陡坡道路。生态叙述强调「缺席清单」：无 bears、wild boars、monkeys、snakes；同时地热蒸汽 hingya 支援烹煮与制盐，将海水蒸发至最高 50 °C（原文：50 C）。常住人口为 160 人（原文：160），仅轻微下降；隔离性与运输摩擦抑制人口成长与大规模观光化。
Aogashima is a remote Japanese volcanic island about 350 km (original: 350 km) south of Tokyo, administered by the Tokyo Metropolitan Government. The typical route is to fly to Hachijojima about 294 km (original: 294 km) south of Tokyo and then take a ferry for the remaining 64 km (original: 64 km); about 50% of the 3-hour (original: three-hour) crossings are canceled for weather, and even arriving boats can fail to dock and return. A helicopter runs daily, but it carries 9 passengers (original: nine seats) and is typically booked 30 days (original: 30 days) ahead, making landfall probabilistic rather than scheduled.
The island is a nested double-caldera system with ongoing volcanic activity; the last recorded eruption was in 1785 (original: 1785). That eruption forced rescue boats to retreat under ash fall and killed 140 villagers (original: 140) by burns and drowning; the inner caldera, Maruyama, formed from magma and debris. In the Edo period (1603–1868; original: 1603-1868), exile totals show a hazard gradient: 2,300 to Miyakejima (original: 2,300), 1,865 to Hachijojima (original: 1,865), and only 6 to Aogashima (original: six).
Tourism capacity is near-zero: two settlements (Nishigo, Yasundogo) and no hotels, cafes, or convenience stores; meals are provided by minshuku, and visitors often self-supply (e.g., 2 L water bottles; original: two-liter bottles) while walking steep roads. Wildlife notes emphasize absence counts (no bears, wild boars, monkeys, or snakes), while geothermal “hingya” steam supports cooking and salt making by evaporating seawater up to 50 °C (original: 50 C). The resident population is 160 (original: 160) and has declined only slightly, with isolation and transport friction limiting growth and mass tourism.