You may have seen the today's flag yet. No matter in what continent you live. There's a flag granted to all the UNESCO's World Heritage sites, occasionally also used by the entities that protect te sites.
There are many variants of the flag, but you'll find more commonly these two:
The first, red on white, the second like UNESCO flag (white on UN blue). The inscriptions in English ("WORLD HERITAGE") and French ("PATRIMOINE MONDIAL") are always present, but the writing in Spanish ("PATRIMONIO MUNDIAL") can be replaced by the national language of the country where the site is located.
The square stands for the result of human skills (the cultural heritages), while the circle represents the Earth (the natural heritages). The circle also remembers a bell jar, representing protection (the World Heritage Convention itself). The fact the circle and the square are intrinsically united represents the link between cultural and natural heritages.
The logo of the design has a strong simplicity that combines with a flag. The text, however, could be dropped without extra thought (as in some variants of the flag), because the wind would be too strong or too weak to the text be read on the biggest part of time.
Hope you knew more about this flag. Comments are welcome.