Vilnius Cathedral is in Vilnius, the capital city of Lithuania, an eastern European country bordering the Baltic Sea, Belarus, Latvia and Poland.

Cathedral officials in Lithuania spent decades searching for 450-year-old royal treasures hidden before WWII. Photos show the long-lost finds. Photo from the Vilnius Archdiocese / Aistė Karpytė ...

The cache from Vilnius Cathedral, in Lithuania, has not been seen since the outbreak of World War II in 1939, according to a press release from Go Vilnius tourism promotion agency on Wednesday.

According to the Vilnius Cathedral, the set of regalia was first discovered in its basement in 1931, when a flood revealed the burial chambers of the Grand Duke of Lithuania and King of Poland.

Cathedral officials in Lithuania spent decades searching for 450-year-old royal treasures hidden before WWII. Photos show the long-lost finds. Photo from the Vilnius Archdiocese / Aistė Karpytė ...

Cathedral officials in Lithuania spent decades searching for 450-year-old royal treasures hidden before WWII. Photos show the long-lost finds. Photo from the Vilnius Archdiocese / Aistė Karpytė ...

Cathedral officials in Lithuania spent decades searching for 450-year-old royal treasures hidden before WWII. Photos show the long-lost finds. Photo from the Vilnius Archdiocese / Aistė Karpytė ...

Cathedral officials in Lithuania spent decades searching for 450-year-old royal treasures hidden before WWII. Photos show the long-lost finds. Photo from the Vilnius Archdiocese / Aistė Karpytė ...