The main subject of this research project was a theoretical analysis of the theme called "Castles of Croatian Zagorje". In relation to the subject, the aim of the research was to define certain findings in accordance with the collected relevant information. There are numerous castles in the area of Croatian Zagorje, and only some are preserved today. The baroque period in Croatian Zagorje was marked by the construction of castles, which for centuries were the focal points of life. The largest number of Croatian Zagorje's castles date back to the 17th and 18th centuries, and they were built under the influence of the Austrian architectural school. Each of the castles from this area has been renovated over the centuries and it can be said that every renovation changed the character of a particular castle as well as the original look in the landscape. In the area of Croatian Zagorje there are baroque classicist castles and castles built and renovated with the ideas of romanticism and historicism. Also in this final work a theoretical contribution was provided to the examples of Trakošćan, Veliki Tabor, Maruševac, Klenovik and Old Town Varaždin. Each of the aforementioned castles hides a lot of historical stories and events, and every historical story provides a certain trace of the past.