Shortly after marrying Anna Rosina Grafenweger in 1672, Valvasor acquired the castle of Bogenšperk/Wagensberg near Litija (Littai), where he arranged a writing, drawing and printing workshop. Valvasor spent a fortune on the publishing of his books; towards the end of his life, his debts forced him to sell Bogenšperk Castle.
Valvasor was a pioneer of study of karst phenomena. Upon the proposal of Edmond Halley, who was not only an astronomer but also a geophysicist, his extensive treatise on the hydrology of the intermittent Lake Cerknica won him a Fellowship of The Royal Society in London.
His most important work remains the monumental The Glory of the Duchy of Carniola (original title: Die Ehre deß Herzogthums Crain, Slava vojvodine Kranjske in Slovenian), published 1689 in 15 tomes.
Some of the graphics from The Glory of the Duchy of Carniola are also used in digital NFT collages of artist Norma De Saint Picman for the promotional and marketing purposes for the upcoming exhibition on 31st of May in Bogenšperk Castle.