Banksy making his mark on an old levee wall.
Can't believe this one is still there. After a few months, they usually get painted over or torn down.
1. unyielding; not lessening in severity, intensity. strength, or pace.
3. steady and persistent; unremitting: the relentless beat of the drums.
synonyms: hard, fierce, unstoppable, unbroken, bound and determined, timeless.