Explanation:

 Context: The Archaeological Survey of India (ASI) recently declared that it has added six structures to the list of monuments of national importance, taking the total number to 3,693.

With 506 monuments under its belt, Karnataka continues to top the list in South India, followed by Tamil Nadu (413). Nationally too, Karnataka is in the second place after Uttar Pradesh, which has 745 such monuments.

The six monuments declared as Monuments of national importance in 2018 are:

1. Old High Court Building in Nagpur, Maharashtra.
2. Haveli of Agha Khan in Agra.
3. Haveli of Hathi Khana in Agra.
4. Neemrana Baori in Rajasthan’s Alwar district.
5. Group of Temples at Ranipur Jharail in Odisha’s Bolangir district.
6. Vishnu Temple in Kotali, Pithoragarh district, Uttarkhand.

What is an Ancient Monument?

According to the Ancient Monuments and Archaeological Sites and Remains Act, 1958, any structure, sculpture, inscription, etc., which is in existence for not less than 100 years is termed ancient.

About ASI:

The Archaeological Survey of India (ASI), under the Ministry of Culture, is the premier organization for the archaeological researches and protection of the cultural heritage of the nation.

Functions: Maintenance of ancient monuments and archaeological sites and remains of national importance is the prime concern of the ASI. Besides it regulate all archaeological activities in the country as per the provisions of the Ancient Monuments and Archaeological Sites and Remains Act, 1958. It also regulates Antiquities and Art Treasure Act, 1972.
The Archaeological Survey of India (ASI) was formed in 1861 by a statute passed into law by Canning, with Alexander Cunningham as its first Archaeological Surveyor, to excavate and conserve India’s ancient built heritage.