The flat riverscape and cows and scudding clouds just outside the town of Pauillac make me feel as if I'm in the Netherlands. Not entirely inaccurately, since it was Dutch engineers who drained this land in the 17th century and allowed vines to flourish. As we pedal away from the river, though, the landscape becomes all French. Golden chateaux of elegant sunniness sit amid crosshatched rows of vines. The road is framed in poplar trees.
I'm on a Uniworld river cruise aboard SS Bon Voyage, now docked at Pauillac on the Gironde Estuary north of Bordeaux. When it comes to wine, there's no better place to be. Or no more expensive, anyway.
Three famous grand crus - Lafite Rothschild, Mouton Rothschild and Latour - are produced in Pauillac's vineyards. The wider Medoc area is perhaps the world's most illustrious wine region, its hundreds of wine chateaux pocket-sized but prestigious.
This is an excursion risking deference and pretentious wine-speak, but fortunately we are rescued from such a fate by local tour guide Christiane, who has an earthy turn of phrase, tangled hair and too much love of cycling to be overawed by the wine country she takes us through. ''You know, the Medoc people were isolated for centuries on this peninsula, they married each other too much, they're all halfwits.''
Well, perhaps not the ones who produce what many consider the epitome of Bordeaux wines: full-bodied, complex reds that mature well in the bottle. They come from grapes grown low on vines that are tightly trimmed sideways to produce a small yield but impeccable quality, Christine explains.
We arrive at Chateau Pichon Baron, one of Pauillac's greatest estates. Here a classic French chateau with pepper-pot towers and mansard roofs is fronted by an uber-modern, circular winery. The cellar sits beneath a reflecting pool. Apparently, there's money aplenty in producing world-famous wines.
Onwards through the countryside, Chateau Lagrange is almost as fine. The chateau is another pile of golden-coloured limestone, this time flanked by a Tuscany-inspired tower and fronting an artificial lake where swans paddle. Everything on this estate is clipped and scrubbed and gleaming. We take a tour of the high-tech cellars before indulging in a wine tasting.
The Fiefs de la Grange 2013 is fresh and sharp like a teenager, aggressive with tannins and acidity. Christine calls it easy-going, with flavours of blackberry and a hint of pepper and nutmeg.
The Chateau Lagrange 2011 is more adult, the sort of wine that makes sommeliers talk about aromas of damp forest and mushrooms. The tannins have been smoothed out, though maybe not quite enough just yet.
''It's the sort of wine I'd give to my in-laws,'' says Christine. ''But keep it for another 10 years and it will only be for good friends and grand celebrations.''
We cycle off through the countryside with a happy Bordeaux buzz, sun on our faces, river in the distance. When we're all back at home, friends will ask us what we did. What can we say, except that we just cycled across the vineyards? But we did it in a special place, and were happy, and surely days don't come much better than that.