Abstract: Lid for a container, in particular a liquid container, comprising an opening (2) for filling the container with its contents from above, the opening being closable by means of a pivotable closure element (3) mounted on the inner side of the lid so as to be rotatable about a first axis (X), the axis (X) being horizontal when the lid is located on top of the container, the closure element (3) comprising a part (4) for closing the top opening of the container, the part (4) being located on one side of the axis (X), and a part constituting a counterweight () of the part (4) on the other side of the axis (X). A pivotable bias element (6) is provided between the closure element (3) and the lid (1), the bias element (6) falling by gravity on the counterweight part (5) and causing that the closing part (4) is being pressed to the opening (2).