The Ancient Monuments and Archaeological Sites and Remains Act, 1958 defines an ' Ancient Monument ' as follows:-

Ancient Monument means any structure, erection or monument, or any tumulus or place of interment, or any cave, rock-sculpture, inscription or monolith which is of historical, archaeological or artistic interest and which has been in existence for not less than 100 years and includes-

• Remains of an ancient monument.
• Site of an ancient monument.
• Such portion of land adjoining the site of an ancient monument as may be required for fencing or covering in or otherwise preserving such monument.
• The means of access to, and convenient inspection of, an ancient monument.

The section 2(d) defines archaeological site and remains as follows:

Archaeological site and remains means any area which contains or is reasonably believed to contain ruins or relics of historical or archaeological importance which have been in existence for not less than one hundred years, and includes-

• Such portion of land adjoining the area as may be required for fencing or covering in or otherwise preserving it, and
• The means of access to, and convenient inspection of the area;

The Archaeological Survey of India (ASI) under the provisions of the AMASR Act, 1958 protects monuments, sites and remains of national importance by giving a two-month's notice for inviting objections, if any in this regard.

After the specified two-month's period, and after scrutinizing the objections, if any, received in this regard, the ASI makes decision to bring a monument under its protection.

There are at present more than 3676 ancient monuments and archaeological sites and remains of national importance. These monuments belong to different periods, ranging from the prehistoric period to the colonial period and are located in different geographical settings. They include temples, mosques, tombs, churches, cemeteries, forts, palaces, step-wells, rock-cut caves, and secular architecture as well as ancient mounds and sites which represent the remains of ancient habitation.

These monuments and sites are maintained and preserved through various Circles of the ASI spread all over the country. The Circles look after the research on these monuments and conservation activities, while the Science Branch with its headquarters at Dehradun carries out chemical preservation and the Horticulture Branch with its headquarters at Agra is entrusted with the laying out gardens and environmental development.