Agra, May 17 -- The wooden stairs used to access the main marble platform of the Taj Mahal are being replaced with new wooden stairs. However, this time, the wooden frame has been replaced by a steel one to minimise shaking. These 22 stairs to go down were replaced on Friday and the other set, used to climb up to the main platform, is to be replaced next Friday (when the Taj is closed for maintenance). Kalandar Vij, senior conservation assistant, Archaeological Survey of India, Taj Mahal, said that the stairs used to shake because of the wooden frame. As such, the frame used this time is steel, but the stairs are wood. "The wooden stairs, in use since 2012, had become slippery, so they were replaced with a new set of wooden stairs. Thousands of tourists use these stairs after entering the main mausoleum and thus need replacement," Vij said. 'Saal' wood of high quality has been used, with the surface roughed up so it does not get slippery soon, Vij added. The original stairs are marble, but due to rampant use, these marble stairs had become slippery, posing a risk to tourists. The ASI official said the marble stairs were covered with wooden slabs in 2012-2013. The 17th Century monument is visited by 20,000 to 25,000 tourists on average daily, but the number rises in winter with more foreign tourists who avoid the summer months. It is a Unesco-listed World Heritage site under the supervision of the Supreme Court....