It is the castle structure located near Uzunburun Village of Yunusemre District in Manisa, and thought to belong to the Byzantine period. Claimed by some researchers to be a fortified monastery, the possibility of the structure being the Monastery of Sosandra mentioned by Gregoras in Magnesia (Manisa) is focused on.
Another claim about the castle is that it has been built by Byzantines for preventing Turkish raids in the 13th century. Construction method of castle walls and dating of pottery remains found in the vicinity support this claim.
The castle has begun to be called Yoğurtçu Castle (Yoghurt Maker's Castle) after Yörükan groups, who have succeeded in settling in the region, despite all acts to hold them back, started to use the castle for yoghurt making and storage.
The castle is planned in accordance with an almost-squarely-shaped plan. It has both an interior castle section and an exterior castle section fortified with towers. The castle is said to be abandoned during the Ottoman period, after being damaged by cannon shots on purpose, for the castle not to be used again.