Agundaborg is connected to the Helge Å water system, a communication route that starts in Åhus on the baltic shores.
It is believed that the Agundaborg farm was established on Brånanäset during the second half of the 1200s. The layout of the courtyard forms an architectural whole, revealing a deliberate plan that should mean that the farm was built at the same time.
The "open" layout means that Agundaborg does not resemble the typical image of a medieval castle. The farm more closely resembles the 13th century palaces Alsnö house and the palace in Vadstena. These sites had no defensive devices to speak of, but above all constituted unfortified royal residences (Lovén 1996:104ff).
The most remarkable thing about Agundaborg is the presence of a building that was probably a courtyard chapel.
Agundaborg is located in a lake that is part of Helgeå's water system. In this area there are two more castles, Vedåsa and Rönnäs, which are located 400 meters apart on both sides of Helgeå a couple of kilometers south of Agundaborg. All four of these "castles" are located along the communication route that ran along Helgeå. The communication route started in Åhus and Vä and continued over Möckeln and Agunnaryd to Ryssby before continuing towards Berga and Rydaholm. In particular, the facilities at Vedåsa and Rönnäs, but also Källarholmen have been located so that they have been able to directly control transports on the water. Sources from the late Middle Ages and the 16th century indicate that this road was primarily important as a an important winter road.
Agundaborg is the oldest settlement in the parish.
The 'saga', story regarding Agundaborg goes as follows:
A very long time ago, Lady Agunda lived in her castle by the lake Agunnaryd. She was a Christian and built the first church in the area. Heathen knights threatened to attack her. However she was saved by a miracle.