A glass and steel walkway is to be built across Rome’s Trevi Fountain, restricting access to visitors as the water is emptied ahead of a thorough scrubbing.

Only a few people will be allowed on the walkway at once in what the city authorities say will be a likely precursor to charging an entrance fee to the baroque monument.

The city announced in September that it wants to introduce a tourist fee to tackle overcrowding at the landmark, which attracts millions of visitors a year.

The walkway, which will be constructed later this month, will allow visitors to have a close-up view of technicians who will clean the fountain’s shallow basin of grime, calcium deposits, bacteria and weeds growing in cracks.

The huge fountain features small brackets made of bronze, lead and iron which over the years have leached orange stains onto the monument’s travertine and marble blocks.