With some exceptions, what you'll be traveling to see are churches and monasteries—the statement-making structures that princes, metropolitans (leaders of the Orthodox church), and merchants in old Russia built to display their largesse and power. Because most civil and residential buildings until the 18th century were constructed from wood, these religious buildings, constructed of stone, have best survived the ravages of time, invading armies, and fire. Today, many are being returned to their original, ecclesiastical purposes, but most are still museums. In either instance, neglect and funding shortages have taken their toll on preservation and restoration efforts, and at times it can be difficult to imagine these historic monuments in their original glory.
Moscow Environs. Don't worry if your schedule's tight. Day trips from Moscow bring spectacular sites within easy reach. At Sergiev Posad, a working monastery, you can see how Russian Orthodoxy has clawed back a place for itself in post-Soviet society. Tolstoy admirers will get a better measure of the man with a visit to his peaceful estate at Yasnaya Polyana.
The Northern Golden Ring. Here lies a scattering of ancient towns—Pereslavl-Zalessky, Rostov, and Yaroslavl. The first two are pretty and small, and the third is a lively city where the centuries of sights can be rooted out among all the trappings of modern, urban Russia.
The Eastern Golden Ring. Rich in stunningly varied churches and monasteries, Suzdal (population 12,000) is a strong contender for most beautiful town in Russia. Vladimir is a worthy neighbor, especially given the presence of the Church of the Intercession on the Nerl, a few miles away.