Aokigahara Forest — Sea of Trees at Fuji's Base

**Trail etiquette and safety:** The forest is safe when staying on marked trails. The Nature Trail and Bat Cave Trail are well-maintained with colored ribbons and signage every 50 meters. Do NOT leave marked paths — the lava substrate makes navigation extremely difficult, and cell phone GPS signals are unreliable under dense canopy. The forest's reputation attracts some visitors with curiosity about darker themes — treat the forest with respect and focus on its natural value. **Ice cave exploration:** Narusawa Ice Cave (鳴沢氷穴) and Fugaku Wind Cave (富岳風穴) are lava tube caves formed during the 864 AD eruption. Narusawa Ice Cave features year-round ice formations even in summer due to cold air trapped in the cave (temperature 0–3°C year-round). The caves require descending steep stairs and low ceilings (160cm height at narrowest) — bring a jacket even in summer and wear sturdy shoes. **Photography:** The forest interior is dark (heavy canopy blocks sunlight) — bring a camera capable of low-light photography or use long exposures on a tripod. The twisted tree roots growing over black lava create alien-like compositions. Early morning light (7:00–9:00) filters through the canopy at oblique angles, creating atmospheric shafts of light. **Volcanic context:** Combine the forest with the nearby Lava Tree Molds (溶岩樹型) — hardened lava formations that formed when molten lava engulfed standing trees during the 864 AD eruption. The trees burned away, leaving hollow cylindrical caves in the lava. Located 10 minutes from the Nature Trail entrance.