At least 13 people were killed after a van ploughed into crowds on Las Ramblas. Dozens more were injured.
Overnight the vehicle involved was towed away under a tarpaulin and police finished their forensic work.
After the London Bridge attack, it took officials 11 days to reopen Borough Market while the Met carried out forensic investigations.
In Barcelona, Las Ramblas has reopened the morning after the attack – but with a heavy police presence