London\'s stone buildings are being eroded by people urinating against them. In Westminster it has become such a problem that the council is installing open air urinals on the outside walls of some of the West End\'s buildings at weekends.

Initially, 13 of the urinals are being fixed to buildings such as the National Gallery in Trafalgar Square in the discreet corners that the council calls \'wet spots\'.

Some of the urinals will be permanently plumbed in but locked closed during the day. Others will be temporary, being put in position on Friday and Saturday nights and removed for cleaning the following mornings.

The idea of locking or removing the units during the day is so that people are not encouraged to use them during daylight. Currently the problem only occurs at night.

The open air urinals will start to be seen in Westminster in July. The council also intends to introduce a by-law making it an offence to urinate in a public place, which it currently is not as long as indecent exposure is not involved. The discussion has been of fines of up to £500.

It is not only in London that a urinating public is causing damage to stonework. NSS reported last year of the attempts of the Helsinki authorities in Finland to tackle the problem by introducing a special police squad to patrol the city at night specifically to deter phantom urinators.