The city's "self cleaning" Millennium Spire has cost €1.1m to keep its shine since it was erected six years ago.
Extensive cleaning and maintenance programmes have been needed on the landmark monument, which is one of the tallest scuptures in the world and is too high for normal repairs.
The self-cleaning properties of the Monument of Light, which was supposed to keep its sheen as the city's rain washed down its slightly slanted sides, have proved a dismal disaster.
The metal has become badly smeared and joints between individual sections have become more obvious.
And the lights at the top have failed on at least five occasions, when the 1,200 bulbs inside were supposed to last for at least 20 years.
Dublin City Council says €324,868 has been spent this year on lighting repairs and a major cleaning operation.
Because of the Spire's height, a huge crane had to be put in place to carry out the operation.
Last year, the council spent a further €435,633 on the same type of cleaning and lighting repairs.
In 2006, maintenance of the spike cost €238,432 and between 2003, when it was erected, and 2005 the council spent a further €180,00 on maintenance and cleaning. The massive cleaning bill is in addition to the €5m spent on construction.
Dublin City Council says that 2007 and this year saw "exceptional years" with major lighting repairs and cleaning.
The lower section of the Spire has to be cleaned every morning at 7am and the first 12 metres are washed thoroughly four times a year.
The landmark was designed by the architectural firm of Ian Ritchie, a British- based designer.