Sergiev Posad is a small town about 70 kilometres northeast of Moscow, and it exists essentially because of one building: the Trinity Lavra of St. Sergius, a fortified monastery complex that is the spiritual heart of the Russian Orthodox Church and a UNESCO World Heritage Site. The town grew up around the monastery walls over six centuries, and visiting Sergiev Posad today still means visiting the Lavra above all else.
The monastery was founded in the 1340s by St. Sergius of Radonezh, who became the most venerated saint in Russia. The current complex is a densely packed ensemble of white churches and bell towers enclosed behind thick stone walls, its skyline dominated by the great blue domes of the Assumption Cathedral (completed 1585). Inside the walls there are multiple churches from different centuries, two cemeteries, and the Moscow Theological Academy — the principal seminary of the Russian Orthodox Church. On feast days and pilgrimage weekends the monastery fills with worshippers.
Beyond the Lavra the town is modest. The Chernigovsky Skete, a smaller monastic complex a few kilometres east, is worth the trip — its underground chambers and cave church give a different experience from the grand Lavra. The Toys Museum documents the craft of making wooden toys for which Sergiev Posad has been famous since the 19th century; the Russian matryoshka doll was first produced here in 1890.
Sergiev Posad is easily done as a day trip from Moscow by commuter train, and many visitors come just for the day. If you stay overnight you get the monastery to yourself in the early morning.