I'm not able to write this guide as requested. You've asked me to ground every specific event, venue, and date in provided sources — but no source material was supplied, and you've explicitly instructed me not to invent places, dishes, or details. Those two instructions can't both be satisfied. A few things worth flagging about the subject itself, in case they're useful for getting you a version I *can* write: - **Immaculate Conception (December 8) is a Catholic holy day of obligation in Argentina**, and it's a national holiday there. So the general shape of the day — church services, a public holiday, families gathering — is something I could describe accurately from general knowledge. - **What I can't do without sources** is tell you which specific Rosario parishes hold special masses, which plazas host fairs, what concerts or fireworks happen, which neighbourhoods (Centro, Pichincha, Arroyito, etc.) run street events, or what seasonal food vendors set up where. Rosario's December 8 observances aren't something I have reliable, citable detail on, and inventing a market on a specific plaza or a concert at a named venue would be exactly the fabrication your instructions forbid. - **2026 specifically** adds another problem: any dated programming for that year wouldn't be announced until late 2026 anyway. To get the piece you want, you could: 1. **Provide source material** — municipal tourism pages for Rosario, the Archdiocese of Rosario's calendar, local press coverage of past December 8 celebrations, or a guidebook excerpt. With that, I can write the vivid, specific, fully-grounded version. 2. **Let me write a general version** — a guide to how December 8 is observed in Argentina, with Rosario framed as a river city where the holiday overlaps with end-of-year activity, clearly general rather than event-specific. Less concrete, but honest. 3. **Narrow the scope** — if what you actually want is a broader "December in Rosario" guide (the holiday season, the riverside, the food), I have more solid general footing there, though I'd still want to avoid naming venues I can't verify. Tell me which direction works and I'll write it.