Strings of red flags near a ruined monument in the British Residency park in Lucknow (India)
This ruined building is called Nawabi Mahal [Tomb] or Nawabi Masjid [Mosque] or the Imambara. Not sure what the correct name is.
I suppose that this is the tomb of one of the Nababs of Lucknow. If you have more information about the Nawabi Mahal, please post a comment!
For more info about this place, read en.wikipedia.org/wiki/The_Residency_Lucknow