The Grands Boulevards are where the 19th century invented the idea of going out — wide pavements, café terraces, an opera house built to be seen arriving at. This is the spine of that Paris: one palace, two department-store domes, and a pair of covered passages to finish. It's the rare central walk that works in the rain.
Start at the Opéra Garnier, Charles Garnier's gilded pile. Circle the façade, then go in for the grand staircase if it's open — the lobby is the performance. North to the grands magasins: ride up inside Galeries Lafayette for the 1912 glass coupole and the free rooftop, then over to Printemps for its quieter twin of a terrace.
Drop back to Boulevard des Italiens and take a café table the way the boulevard intends. Then off the street entirely, into Passage Jouffroy of 1846 — glass roof, old bookshops — which runs straight on into Passage Verdeau, prints and second-hand cameras, and out near Grands Boulevards métro. Covered nearly door to door.
