The Barrio de las Letras is the quarter where Spain's Golden Age lived and wrote — Cervantes, Lope de Vega, Quevedo, all within a few hundred metres — and the city has set their verses into the pavement so you read the place as you walk it. Two and a half kilometres, best in the late afternoon when the cafés and squares fill. Walk it with your eyes down, then up.
Start at the foot of Calle de las Huertas and climb, reading the brass lines underfoot. Detour to the Casa-Museo Lope de Vega — the great playwright's house, on the street named for his rival — and the Convento de las Trinitarias, where Cervantes lies behind a still-cloistered wall. The address joke runs both ways and the quarter knows it.
Open out at Plaza de Santa Ana, Lorca's statue and Hemingway's old bar, then climb Calle del Prado past the bookshops and the Ateneo's hushed reading room. End at the Café Gijón, pouring for arguing writers since 1888 — a coffee at a marble table, then the Metro at Sevilla.