The ILNM is the first federal inventory issued by the Federal Council on the basis of the Federal Act on the Protection of Nature and Cultural Heritage (NCHA). It came into effect in four stages:

• stage 1 in 1977, comprising 65 sites
• stage 2 in 1983, comprising 55 sites   
• stage 3 in 1996, comprising 33 sites 
• stage 4 in 1998, comprising 9 sites

The ILNM is based on the Inventory of Landscapes and Natural Monuments to be Preserved (KLN Inventory), which was issued in 1963 by three associations - the Swiss Conservation Association (SBN, now Pro Natura), Swiss Heritage (SHS) and the Swiss Alpine Club (SAC). The ILNM gradually replaced the KLN Inventory served as a set of binding guidelines for the authorities.

"ILNM enhancement" project

Despite some improvements in recent years, the goals specified for the protection of landscapes of national importance have only been partly attained. For this reason, a project is currently under way designed to improve the protection of landscapes and natural monuments of national importance, thereby enhancing these valuable sites.