The Indian Museum as also several important office buildings and plush hotels switched off their lights here on Saturday as Kolkata joined the rest of the world in observing Earth Hour.

The multi-storied Tata Centre office building, five star hotel Taj Bengal as also a number of other hotels and eateries kept their lights switched off between 8.30 p.m. and 9.30 p.m., in a token gesture to raise public consciousness about the Greenhouse Effect, sources said.

In the districts, lights were turned off during the said period as part of the global programme, that also highlighted the need to use energy-efficient tubes and bulbs.