Out of these, 11 monuments are in Uttar Pradesh, two each in Haryana, Delhi, Maharashtra, and Rajasthan, while one each in Assam, Arunachal Pradesh, Uttarakhand, Madhya Pradesh and West Bengal.
"24 monuments are missing/untraceable," Culture Minister Mahesh Sharma said in a written reply in Lok Sabha.
He said a CAG report of 2013 had stated that 92 protected monuments were missing.
Sharma, however, said vigorous efforts to locate the reportedly untraceable monuments by respective field offices of ASI found that as many as 24 monuments/sites were untraceable, adding that 42 were physically existed, 14 affected due to rapid urbanization, and 12 submerged under reservoir/dam.
To another query, he said, "ASI has entered into an MoU with National Remote Sensing Centre/Indian Space Research Organisation (ISRO) for preparation of satellite based maps indicating protected, prohibited and regulated areas with respect to all centrally protected monuments.