Foam is a Redanian city on the Pontar Delta. The Malatius and Grock Company hires Geralt to travel on their one of their barges between Foam and Novigrad to ensure they are not attacked by monsters.
It is also mentioned in the short story "Trochę poświęcenia" ("A Bit of Dedication") is a short story in the Miecz przeznaczenia ("The Sword of Destiny").
cs:Pěna