The Castellana axis: the great north-south spine
Cibeles to Nuevos Ministerios — fountains, Colón, and an open-air sculpture museum under a bridge. This is a Claude-drafted route awaiting the editor's walk.

1. Plaza de Cibeles
The fountain Madrid celebrates its football wins around, with the wedding-cake Palacio de Cibeles — once the central post office, now the city hall — looming behind. Start here; everything north is one long straight line. The terrace café upstairs has the view if you want to take the axis from above first.

2. Plaza de Colón
A vast hard square dominated by the largest Spanish flag in the country and a column to Columbus. Under the plaza sits the Centro Centro cultural space; above it, the city's noise. Cross it briskly — it's a place to pass through, and it's where the *Paseo de la Castellana* properly begins.

3. Museo de Escultura al Aire Libre
The open-air sculpture museum slung under and around the *Juan Bravo* flyover — Chillida, Miró, Julio González and others, set among concrete pillars and traffic. The signature piece is Chillida's suspended 'Sirena varada', hung from the bridge itself. Free, never crowded, easy to walk straight past; don't.

4. Museo Lázaro Galdiano
A financier's mansion a block east, stuffed with the collection he never stopped buying — Goya, Bosch, ivories, clocks. You don't have to go in, but the building and its garden are a calmer counterpoint to the avenue's roar. A good place to step out of the traffic for half an hour.

5. Gregorio Marañón and the towers ahead
Where the avenue widens and the office towers start to crowd in. The median greens up here into a proper walkable strip with benches under the planes. Walk the centre, not the edges — the *Castellana* is best taken straight up its spine.

6. Nuevos Ministerios
The long 1930s government block by Secundino Zuazo closes this stretch of the avenue, its arcaded courtyard open to walk through. The metro hub underneath gets you anywhere. End in the courtyard, out of the traffic, with the towers of AZCA rising just to the north.

The Castellana axis: the great north-south spine