A valve has a housing which has at least two fluid openings, through which fluid can flow, and a further opening, at least one valve seat which is assigned to one of the fluid openings, and at least one closure member which is adjustable to release and/or close the at least one valve seat, the at least one valve seat which adjoins a cavity through which fluid can flow being formed on a housing part. The valve includes a sensor device which closes the opening in a fluid-tight manner and can acquire data about the fluid is arranged in the further opening. A valve island is furthermore described.