Jim Keppy, age 11, of Niagara Falls, Ontario, Canada, for his question:

WHY ARE SOME RUSSIAN TOWERS ONION SHAPED?

The famous onion shaped tower domes seen on a number of the buildings in Russia are actually a carry over from the Middle Ages.

Perhaps the most famous building in this architectural mode is the magnificent Saint Basil's Church in Moscow. The building is more than 400 years old.

The style of architecture featuring the onion shaped domes is called Byzantine. The style inspired most of the architecture of the Balkan countries during the Middle Ages and influenced Russian architecture for hundreds of years. Saint Basil's, built in the 1500s, is perhaps the most outstanding example of the architectural form. Byzantine forms also contributed heavily to Islamic architecture.