There is so much history at this gorgeous site. The main gate itself is over 1,000 years old. If you can come away from crowded times, the place is not too busy. The ticket office will try to sell you the combo ticket to visit multiple buildings. While the side buildings (bakery, patriarch's quarters) are interesting, the best attractions are the main church and the gate tower.
Sad thing is the fact that Sophia is falling apart. Unlike Lavra, which is now maintained by the money of the Orthodox Church, the Ukrainian government is supposed to keep Sophia up and is not doing a great job. There is a chance that the World Heritage status may be revoked if certain standards of maintenance are not met.
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