Arganzuela is where Madrid did its industrial work — the first railways, the slaughterhouse, the warehouses — and the Delicias station is the monument to all of it. This walk follows the iron and brick of working Madrid from a grand dead terminus down to the river.
Start under the canopy of the Estación de Delicias, the city's first great station, opened in 1880 and engineered in glass and wrought iron. The trains stopped in 1969; now it holds the railway museum, rows of black locomotives beneath the original span. Go for the shed itself — the roof is the exhibit. Out along the Paseo de las Delicias, past the auto shops and wholesalers of a quarter that has always made and moved things.
West to Matadero, the old municipal slaughterhouse turned cultural centre, its brick pavilions kept honest in the conversion. Wander the courtyards, then cross to the river at Madrid Río, the park laid over a buried motorway, and look back at the brick against the water. Loop east to Méndez Álvaro for the metro home.