Since the 1960s, large cities have been putting their coat of arms on manholes. In the 1980s, an official from the Ministry of Construction, wishing to raise public awareness of urban hygiene, began to design the manhole covers. From now on, each municipality will have its own design and will use the manhole cover as a tourist promotion medium. For this purpose, the municipality calls upon the creativity of its officials, subcontractors or directly upon the taxpayers who send in their proposals.
Very often, the designs represent the assets of the city; a historical monument, a local speciality, emblematic animals or plants. Sometimes famous mascots adorn the round cast iron. The aesthetic diversity has attracted the attention of the local population and visitors, so that many local institutions, both public and private, have been riding the wave. Trading cards were published and a photo collection was produced. Replaced, sometimes stolen, plates are now on the second-hand market and are being sold at auction.