Jan Murray, Age 12, Of Nashwaaksis, N.B., Canada, for his question:

How old is Mexico City?

The sun drenched capital of Mexico is older than any city in North America. It dates back hundreds of years before Columbus was even born. For its flat and fertile valley is a natural site to build a city. The Aztec Indians were talented builders who governed most of Central America. Their handsome city of Tenochtitlan, with its stone buildings, carvings and pyramid temp1es stood on the site which is now Mexico city.

We do not know the age of the old city of Tenochtitlan, for it was razed and its stones used as the foundation of Mexico city. The Aztecs were conquered by the Spanish in 1519, and the building of the present city was soon started. The cathedral, the national palace, the arcades and main buildings of the central plaza mayor de la constitucion data back to the early years of the 16th century, but no one knows the age of the former cities that stood upon this favorable site.