Otto Pius Hippius
Otto Pius Hippius (, Saint Petersburg — , Saint Petersburg) was a Baltic German architect, particularly noted for several buildings in present-day Estonia. Otto Hippius was born in the family of a painter and lithographer Gustav Adolf Hippius who taught his son Art since the earliest childhood. At the teenage age Otto Hippius studied in Germany and in 1849 he graduated with honors from Karlsruhe Institute of Technology. Since 1849 to 1851 he studied at the Russian Academy of Arts in Saint Petersburg and upon graduation continued working as an architect and teacher at several art schools. In 1864 Hippius became a member of the Russian Academy of Sciences and in 1879 he became a professor.

Among his works Sagnitz Manor (now in Sangaste) in southern Estonia, built for Count Friedrich Wilhelm Rembert von Berg between 1879 and 1883, Münkenhof Manor (now in Muuga), built for painter Carl Timoleon von Neff between 1866 and 1873, Charles' Church in Reval (now Tallinn), constructed between 1862 and 1870 and Alexander Church (et) in Narva, constructed between 1881 and 1884.