Modder Ura released a "Restoration Mod" in 2024 that re-enables these levels by forcing the game to skip missing script triggers. The AI is buggy, but walking through these abandoned levels is like finding a lost archaeological site.
Most active Tenchu 3 modding happens on forums like The Lair of the Shinobi (Nindo) and PCSX2 Mods Hub . Look for .pnach files (for emulated cheats) or texture packs in .png format. tenchu 3 mods