Wastewater treatment plant and method for treating wastewater, and wastewater treatment system

Wastewater treatment plant having a plurality of filter layers disposed one under the other for purifying the wastewater, wherein in each case at least one feeding device for feeding wastewater to the filter layer and at least one discharge device for discharging the water purified by the respective filter layer is associated with each filter layer, characterised in that in the case of at least two of the filter layers (110), the feeding device (200) is directly fluidically connected to a wastewater feeding line (400) and the discharge device (300) is directly fluidically connected to an intermediate store (600) such that the unfiltered quantity of wastewater fed to the respective filter layer (110) is purified exclusively by this filter layer (110), wherein the wastewater treatment plant comprises a central shaft for discharging the purified wastewater into an intermediate store (600) by utilising gravitational force.