Cartoon Fortress in a Subway Tunnel

Cartoon-style fortress embedded inside a dim subway tunnel. Bold black outlines, saturated colors. A stone fortress with crenellated towers and a rounded gate rises from the tunnel floor between concrete walls. Mossy textures on the fortress, warm amber light from overhead lamps, and cool blue shadows in the tunnel. Tracks and a distant passing train glow softly. Goofy armored guards patrol the battlements; graffiti on tunnel pillars adds whimsy. Perspective from the tunnel floor looking toward the fortress gate, with a light fisheye exaggeration to emphasize scale. Mood is magical, adventurous, and humorous. Style: 2D cartoon illustration with flat shading and clean lines, kid-friendly.