Region vs District vs Appellation: what's actually on the map

The Wine World Map has three nested layers, and they're not the same as how wine writers casually use the words. Here's what each level actually means in this database.

Region

A region is a big, well-known wine area. The kind you'd put on a map of France for a school assignment. Bordeaux. Burgundy. Champagne. Languedoc. About 380 of these worldwide.

In bureaucratic terms a region usually maps to:

• France's régions viticoles (Bordeaux, Vallée du Rhône, …)
• Italy's regioni (Toscana, Piemonte, …)
• Spain's autonomous communities or large DO families (Rioja, Cataluña, …)
• US AVAs at the broad level (Napa Valley, Sonoma County)

A region has a centroid (lat/lng), a zoom level appropriate for "see the whole thing", and — often — a polygon outline.

District

A district is one level deeper. It's an appellation in the strict sense: AOC, DOCG, DO, DOCa, AVA. Bordeaux contains Médoc and Saint-Émilion; Médoc contains Pauillac; that's three levels.

In our database a district has a parent region_id, its own centroid, and an appellation_type ('AOC', 'DOC', 'AVA', …). The URL is /districts/<slug>.

The hard call is which historically-loose term to encode at this level. We treat Chianti Classico as a district under Tuscany, not as its own region — even though it's a DOCG. Same for Barolo under Piemonte, Pauillac under Bordeaux, Brunello di Montalcino under Tuscany. Anything more granular (single vineyards, climats in Burgundy, German Einzellagen) doesn't fit and isn't on the map.

Winery

The leaf. A specific bodega, domaine, cantina, Weingut, or château. A point on the map with optional opening hours, website, booking URL, and a flag for whether the cellar door accepts visitors.

Wineries are linked to a region (and sometimes a district). When the OSM import finds a winery that doesn't fall inside any region polygon, it's left orphan-linked by proximity — a Riesling-Silvaner shop in some German hamlet 30 km outside the Rheingau still ends up under "Rheingau" because that's the closest region we know.

What that means when you click

• Click a region in the world view → fly to country, draw region polygons.
• Click a region polygon → fly to region, draw district markers, draw winery markers.
• Click a district marker → fly to district, draw only its wineries.
• Click a winery → InfoPanel with the visit details.

There's no fifth layer. If a region has districts the map shows them; if it doesn't (yet), the wineries appear directly under the region. That's the whole hierarchy.