Liubice, Archaeological site and cultural heritage monument at the confluence of Schwartau and Trave rivers, Germany.

Liubice is an archaeological site on a peninsula at the confluence of the Schwartau and Trave rivers, about six kilometres downstream from Lübeck's old town. Excavations have revealed a castle with a 100-metre-diameter rampart and a southern gate, a stone church preceded by a wooden one, a harbour, and two suburban settlements. Today the area is a grassy embankment with no visible masonry.

Liubice grew from a Slavic lowland castle at the mouth of the Schwartau, whose oldest rampart is dendrochronologically dated to 819. Gottschalk rebuilt the castle from 1055, and around 1087 a twelve-metre trench cut it off from the mainland, turning it into an island fortress. Under Henry from 1093 it became the residence of the Obotrite prince, with harbour, mint and suburban settlements, until the Rani destroyed it in 1138.

The name Liubice comes from the Slavic root *l'ub- (dear, lovely), probably as a patronymic meaning "settlement of the descendants of L'ub or L'ubomir". The site is an earthwork; no standing church ruins survive, though excavations found a wooden church with a cross-shaped plan (22 by 15 m) beneath a later stone church. Remaining Abodrites held assemblies at Lübeck's Marienkirche into the 13th century, and Slavic legal institutions left traces in Lübeck law.

The site lies about six kilometres downstream from Lübeck's old town, on a peninsula formed by a bend of the Trave and the mouth of the Schwartau, opposite Teerhof Island. It is an unexcavated archaeological monument with no ruins or facilities, so there is little to see beyond the grassed embankment. The ground is uneven and the site is not set up for visitors.

The transformation into an island fortress was a deliberate defense strategy, not an accident, reflecting the settlement's growing importance as a trading post. A purposeful ditch separated it from the mainland, making it much harder to attack.