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.
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.
A piece of interesting data was recorded in 1473 when three quarters of the fortress belonged to Kuneš of Olbramovice. The owner of the castle chose a different piece of land in the southern part of Kácov on the edge of a rocky slope steeply falling towards the Sázava. This slope created a naturally formed fortification which was complemented by an artificial fortification, which since then has disappeared, on the north side. The original aspect of the fortress cannot be envisaged after several reconstructions.
Under the reign of Jan Oktavián Kinský, a serfs’ rebellion arose in the Kácov Estate in 1627 and the rebels also ransacked the fortress. It was only Bnigna Kateřina of Lobkovice who had it reconstructed after1630. A smaller one floored Baroque style chateau was created. Its ground floor was built from stone and the first floor from wood. The chateau was further extended under the ownership of František Scheidler. The Tuscany princess Anna Marie Františka had the dilapidated Kácov chateau, which had not received much attention from its previous owners with many debts, reconstructed in the style of a Baroque North Italian noble seat. This reconstruction completely changed the look of the former fortress building, removed the last part of the old fortification and there were only a few foundation walls left from the old building. The new chateau was built on a uneven terrain, therefore its south front which was orientated towards the Sázava had two floors while the north, with the main entrance, had only one floor. The chateau was based on an oblong ground plan whilst the shorter western and eastern sides were decorated with turret like projections. These projections were as tall as the main building and therefore were highlighted with Baroque cupolas. As far as the interior is concerned, the axis of the main chateau building was formed by a passage going through both floors and which, at its highest point, was taller than the roof of the chateau and formed an oblong semi-floor which gave the chateau its typical silhouette. The passages lead to most of the rooms. The interiors had mostly stucco decorations. The richest decor was concentrated in the chateau chapel. The front walls were decorated with murals of various figures in blind windows. The chateau was divided from the square with a simple wall with a Baroque gate. This appearance of the chateau has been preserved practically to date.