Penshaw Monument is red and yellow tonight, in tribute to the victims of the Spanish terror attacks.
The monument has been lit in the colours of the Spanish flag to remember the dead and injured.
The Magistrates Court building in Keel Square will also be lit in red and yellow in solidarity with the people of Spain and the union flag is flying at half mast at Sunderland Civic Centre as a sign of respect for those who were killed and injured in the attacks in Barcelona and Cambrils.
City Council Leader Coun Paul Watson said : "Our thoughts are prayers are with all those caught up in these devastating attacks.
"Sadly scenes like the ones in Barcelona and Cambrils are becoming all too familiar on our streets and it is right and proper that we show our unity with the people of Spain at this very sad time.
"Only by standing together and showing that we will not be cowed by such cowardly attacks on innocent people can we ever hope to defeat the terrorists."
Penshaw Monument and the Magistrates Court building will remain lit for the next three nights in line with the three-day period of national mourning declared by the Spanish Government.