As well as these tar traces on the walkway to Carrer del Doctor Aiguader,
there was also more intentional drawing on the temporary fence boards.
A few weeks later I was to learn from Allan Sekula's text to his photographs New and Old Natural Gas Stations in the section "2007, Metropolitan Images of the New Barcelona" of the MACBA exhibition Universal Archive (23 Oct 2008 - 6 Jan 2009, on which I hope to write something later), that the distinctive graffiti in this park is of a Salvadoran gang, the Mara Salvatruchas, who originated from his neighbourhood in Los Angeles.
Adjacent to this park was a construction site, cut through by the Carrer del Gas.
The setting sun was warm on the facades visible above the fencing.