On December 13, 1923 the tree became a national natural monument.

The site is protected as a natural monument of the city.

In 1967, the lake was protected as a natural monument.

This was an exhibition about natural and cultural monuments of the world.

Many of these rocks are under state protection as natural monuments.

This is a natural monument protected by the laws of that country.

A national natural monument lies in the northeastern part of the city.

After the war, the plain was designated a natural monument on 29th March 1952.

The species was designated as a special natural monument in 1951, and has been protected.

The natural monument included only to the open faces and the rock immediately below the cave.