B4 — the Before Sauna Club — is a sauna-club for adult encounters in Sainte-Luce-sur-Loire, on the eastern edge of Nantes, and one of the region's fixtures for the libertine, gay and LGBT communities alike. Its defining feature is the split programme: the week is divided into ambiances — libertine days, gay days and all-tendencies days — each with its own schedule and door, so check which crowd owns the calendar before you go.

The club presents itself in images as much as text: play spaces ('espaces coquins'), a balneo area, a bar, a terrace and a garden. On public holidays the club stays open following whichever ambiance that weekday normally carries, and the eve of a holiday runs as an all-tendencies night without early closing.

Hours and entry prices are published per ambiance on the club's own site — as image tables the day we read it, so we quote none here rather than risk a stale number; check the Horaires & tarifs page for the current grid. A drinks and food menu is published alongside.

Access is easy from Nantes: tram line 1 towards Beaujoire to Haluchère, then bus 85. Browse our Nantes-area listings for the region's other libertine venues.