Lomonosov (Ломоносов) is a town in the Leningrad oblast (Ленинградская област) of the Russian Federation, situated on the southern coast of the Gulf of Finland.
During Tchaikovsky's lifetime it was known as Oranienbaum (Ораниенбаум), and it was the administrative centre of the Oranienbaum district (Ораниенбаумский уезд) in the Saint Petersburg province (Санкт-Петербургская губерния) of the Russian Empire.
Tchaikovsky in Oranienbaum
Tchaikovsky stayed at a dacha in Oranienbaum during a family holiday in July and August 1854.
Here the composer wrote his earliest-surviving piece, the Anastasie-valse, the manuscript of which is dated 15/27 August 1854.