Lid for a container for filling the container from above, the opening being closable by a pivotable closure element mounted on an inner side of the lid so as to be rotatable about a first axis (X) which axis is horizontal when the lid is located on top of the container. The closure element includes a first part for closing the top of the container located on one side of the axis (X), and a second part as a counterweight on the other side of the axis (X). A pivotable bias element is rotatably mounted on the inner side of the lid on a second axis (Y) which is parallel to the first axis (X). The bias element is biased onto the second part by gravity and causes the first part to be pressed to the opening.