Half of the Čertova zeď ("Devil's wall") National Nature Monument is situated in the municipal territory.

[4] Osečná was most likely founded in the first half of the 13th century, along the trade route which led from the town of Český Dub to Děvín Castle.

At the end of the 16th century, Charles Bieberstein sold Osečná and other villages to Jan Oppersdorf.

The year 1576 was very important, when Emperor Rudolf II promoted Osečná to a town and it got the law to use an urban character and the seal.

The inhabitants of Osečná had to accept Catholicism and they had to pay for a parson from Český Dub too, but they refused.

In 1653, the people from Osečná announced the recatholisation, what means they converted back to the Roman Catholic faith.

[3] In 1634, when Albrecht von Wallenstein was killed, his property reverted to Emperor Ferdinand II, who bequeathed it to General Jan Ludvík Hektor in recognition of his military service.

When he died, his daughter Regina inherited his property, and she went to Vienna's Saint Jacob Convent in 1643, where she became Mother Superior, and donated her manor to this monastery.

[3] On 6 August 1838, Duke Kamil Rohan from Sychrov bought the Český Dub estate.

On this blazon is written one of the main mottos of the Rohans: "Potius mori quam foedar", what means: "Is better to die than to betray".

[5] The Kundratice spa was established as part of the town of Osečná in 1881 and is one of the oldest spas in Bohemia where bog is used as a natural healing source.