arkhangelsk tower, solovetsky monastery, bolshoi solovetsky island, arkhangelsk oblast

15th ancient archangel archipelago architecture arkhangelsk attraction big bolshoi boulders century christianity day famous fortress heritage island landmark list male monastery oblast orthodoxy pilgrimage popular poselok preobrazhensky religion russia saviour sea settlement solovetskiy solovetsky stavropegial stones sunny tourism tower towers unesco vertically walls white world