The best way to explore Porto's shores is by boat. Photos by Erik Nilsson/China Daily

Portugal's wine city and the river valley from which its port pours sculpt the profile of a region shaped by grapes in every sense. Erik Nilsson explores its shores.

Wine wrought the Douro Valley.

Its inhabitants have spent the past two millennia carving livings out of the shale mountains that nosedive into the river, whittling the peaks into terraces clutched by grapevines.

Nearly 50,000 of the region's 250,000 hectares have been lathed into hundreds of liana-wrapped honey-dipper tips.

The world's oldest demarcated wine region remains rugged.

Some residents of neighboring Porto city say of this hinterland: "The women are men. And the men are werewolves."

(The valley folk may take exception.)

This is the home－the sole source－of port wine.

The fermentation of the wine made from grapes here is incapacitated by brandy that's at least 77 percent alcohol to halt fermentation and preserve the sugars that give port its hyperactively saccharine character, relegating it exclusively to the realms of aperitif or digestive.

This beverage is both born of, and has sired, the culture this land has forged－a culture that has, in turn, reshaped the land's contours.

The fruits of local labor bejewel the leaves that sheathe the bouncing topography, festooning verdure plumage with clusters of sapphire, emerald and ruby.

The UNESCO World Heritage site is a place where such wineries as Quinta da Pacheca still squish grapes with human feet.

Visitors prance atop the fruit to traditional music around the September harvest.