The UN migration agency says that more than 63,000 migrants and refugees have entered Europe by sea in 2018.
Forty-two percent of them have arrived in Spain, but many others who undertake the treacherous journey do not survive.
And as crossings to the Spanish coast have surged this year, migrant drownings have tripled, as well.
Spanish authorities have spent months trying to identify remains and repatriate them whenever possible.
Al Jazeera’s Karl Penhaul reports from Tarifa in southern Spain – where burying the unknown has become all too common.