Just west of pl Konstytutsiyi, the gleaming domes of the Pokrovsky Monastery (Intercession of the Virgin) are visible from miles away. The predictably peaceful grounds (enter from pl Konstytutsiyi) have two attractive churches. The smaller and more important of the two is the blue, three-domed Pokrovska Church (1689). As in all Orthodox churches, the altar is under the east-pointing dome, and there's another altar hidden in the basement, which the attendant may show you if you ask.
The church is almost always open for services. The yellow church next to it is the Ozeyansky Church.
