A valve island has at least one valve module and an adapter module, wherein the adapter module includes a first data line and a first voltage supply line, which each extend continuously from an interface on a first front side forming an outer side of the adapter module to an interface on a second side of the adapter module pointing into the valve island. In the adapter module a circuit unit is provided, which within the adapter module is connected to the first data line and/or the first voltage supply line and from which within the adapter module an internal data line and/or an internal voltage supply line proceeds or proceed, which each extends or extend to an interface on the second side of the adapter module.