The castle's center is an old flour mill built in the town of Radomyshl (Zhytomyr Oblast, Ukraine) in the late 19th century by Polish engineer Piekarski.

The collection comprises more than 5000 icons and sculptures (Orthodox, Catholic, and Greek-Catholic), created between the 16th and 20th centuries in different parts of Ukraine.

The Castle's interior combines the features of the Late Medieval and Early Modern periods.

Radomysl Castle's landscape park was created in accordance with modern environmental requirements.

Among them are iris, pink and white lilies, English garden roses, magnolias, and Trapa rossica, a water caltrop, which is listed in Ukraine's Red Book of endangered species.

On 29 October 2009, near the place where the paper mill stood, a monument to Yelysei Pletenetskyi was unveiled.