Part of the Champs-Élysées’ gardens, this “Swiss Valley” was built from scratch in the late 19th century by the park designer Jean-Charles Adolphe Alphand. It is a lovely illusion, where nothing is quite what it appears at first sight. The rocks that form the pond and waterfall are sculptured from cement; so is the “wooden” footbridge. But the space — 1.7 acres of semitamed wilderness in one of the most urban swaths of Paris — has lured me, over and over again. My only companions are the occasional dog walker and the police woman making her rounds.

On a park bench there, I am enveloped by evergreens, maples, bamboo, lilacs and ivy. There are lemon trees; a Mexican orange; a bush called a wavyleaf silktassel, with drooping flowers, that belongs in an Art Nouveau painting; and another whose leaves smell of caramel in the fall. A 100-year-old weeping beech shades a pond whose waterfall pushes away the noise of the streets above. The pond, fed by the Seine, can turn murky, but the slow-moving carp don’t seem to mind, nor does the otter that surfaces from time to time.

The Swiss Valley is one of the most unusual of Paris’s more than 400 gardens and parks, woods and squares. Much grander showcases include wooded spaces like the Bois de Vincennes on the east of the city and the Bois de Boulogne on the west, and celebrations of symmetry in the heart of Paris like the Tuileries and the Luxembourg.

But I prefer the squares and parks in quiet corners and out-of-the-way neighborhoods. Many are the legacy of former President Jacques Chirac. In the 18 years he served as mayor of Paris, he put his personal stamp on his city by painting its hidden corners green.