A waste collection system and a method for assembling a waste collection system

Invention relates to a waste collection system (1) and a method for assembling a waste collection system. The waste collection system comprises - an outer shell (2) being suitable to be arranged at least partly underground; - a waste container (6) to be inserted partly into the outer shell, the waste container comprising: o a frame (7) to be arranged at least mainly above the ground (8); o a top container (9) to be arranged at least mainly above the ground and inside the frame; o a bottom container (12) to be arranged at least mainly underground inside the outer shell; - a cover (16) on the waste container, arranged to be opened for emptying the container; - one or more filling openings (17) arranged on the cover for waste to be introduced into the waste container; - lifting means arranged on the frame, suitable to be engaged by a lifting mechanism (20) by which the waste container can be lifted out from the outer shell and emptied and returned into the outer shell. The frame comprises at least one protrusion (18,19) towards the inside of the frame and the top container comprises at least one corresponding recess (21,22) in which said protrusion is to be fitted in order to firmly attach the top container to the frame.