For a window into the soul of a city, take a stroll along the waterfront: Think of the Seine walkways in Paris, the Copacabana promenade in Rio or the Charles River Esplanade in Boston. Or the nearly 14-mile palm-fringed ribbon called La Rambla, in Montevideo, the capital of Uruguay.

One of the longest sidewalks in the world, La Rambla meanders along the shimmering estuary Río de la Plata, past beaches, wine bars and purple-blossomed jacaranda trees, statues and sculptures, soccer matches and friends engrossed in conversations over cups of yerba mate.

If you go in the summer — as the Northern Hemisphere shivers in the cold — you may find yourself part of a mass migration of locals toting folding chairs to the promenade, turning it into, essentially, the city’s outdoor living room.

The promenade stitches together different pieces of Montevideo, a city of about 1.3 million, socially as well as geographically. On it, you’ll find Uruguayans from all social strata. It’s “the city’s thermometer,” as Natalia Jinchuk, a Montevideo native and author, described it to me.

With my own thermometer dipping and my imagination stoked, I planned an early-winter long weekend in Montevideo, a flower-speckled city that melds Old World and Modernist architecture, to boost my spirits with my own ramble on La Rambla.