Rostiv is one of the oldest Russian cities, mentioned first in 862. Nothing is left from 9th century, and Rostov is now famous for its Archbishop's Court (usually known as Kremlin), built in the end of 17th century by Metropolitan Jonas - and several churches and monasteries from the same time. The fact that all these buildings originate from roughly the same time (and are built in roughly the same style), and a nice location on the bank of big Lake Nero make Rostov one of the most popular tourist destinations. It is one of the Golden Ring cities and is frequently visited by tourists. If you want to do it independently, it is 3-4 hours from Moscow by train, bus, or car.
More info on Rostov on
my external page (currently only in Russian).