Gammel Estrup lies on the road between Randers and Grenaa. On one side of the road is the hill Helligbjerget, which has functioned as a landmark and viewpoint throughout the ages. On the other side stands the manor, large parts of which were built during the renaissance in large medieval red brick. The manor house itself is surrounded by a double moat and its extensive farm buildings.
It is not known exactly when Gammel Estrup was built, but archaeological excavations on the castle mound have revealed building remains from the 14th century. From the Middle Ages, there is also evidence about the periods when the estate was involved in land disputes or suffered damaged as a consequence of war and unrest.
Gammel Estrup was owned by the same family for 600 years, and the earliest parts of the present buildings date from around 1490, when the owner at that time, Lave Brock (died c. 1504), built a stone fortress on the site. Lave Brock was a fiery character, who probably needed a place to which he could retreat in safety. It is said that in 1468 he was personally responsible for killing the Randers merchant Niels Paaske.