In 1720, Frantisek Adam Trauttmansdorff entrusted the renowned Czech architect F. M. Kanka with the construction of a château corresponding to his social status, that of a prominent member of the aristocracy. The château is a typical seat of a nobleman from the height of the Baroque period, decorated by prominent artists such as M. B. Braun, V. V. Reiner and F. A. Scheffler.
Another, younger fortress used to stand in the location of the current chateau. This fortress was probably founded in the middle of the 15th century, after the previous older fortress, located in the south-western direction from Kácov on the left bank of the Sázava nearby Soušice, became dilapidated. Due to the fact that on the turn of the 14th and 15th century Kácov was divided between several owners, it is possible that there were two fortresses existing next to each other over a certain period of time.
The first written reference to the site dates back to 1149 and mentions a convent of the Premonstratensians, founded in the so-called Moon Valley. The Lounovice convent was ruined in 1420 by the Tabor forces that then dominated the whole region. The museum displays findings of the archaeological research of the convent, installed in the château by the National Museum in 1981.
This originally stone stronghold of the noblemen of Janovice, protected by a moat, was gradually converted into a manor house in the Renaissance style, becoming the seat of the Votice branch of the counts of Vrtba in the 17th and 18th centuries. The last major reconstruction occurred in the mid 19th century, when the château received its current, neo-gothic look.