Everyone walks the front of the Prado. This is the walk round the back — the green, literary edge of the museum mile, where Madrid keeps its botanic garden, its book stalls and the king's old church within a few hundred metres of each other and almost no crowds. A morning walk; come before the coaches.
Under three kilometres, mostly flat with one gentle slope. Start in the Real Jardín Botánico, Charles III's garden of 1781, terraced and quiet at opening time — walk the lower beds up to the greenhouse. Out the side and onto the Cuesta de Moyano, the hill of green wooden book stalls that have traded here for a century; browse the spines whether or not you read Spanish.
Climb into the still streets behind the Prado, where the traffic falls away, and find San Jerónimo el Real, the twin-towered royal church where Spain still crowns its kings. The steps out front give the view back over the museum.
Carry on past the Prado's quiet flank to Plaza de la Lealtad and its obelisk, with Banco de España a block on.