Lardea or Lardeya (Bulgarian: Лардея, Greek: Λαρδέα) is a ruined late Roman and medieval fortress, situated near the village of Lozenets in Straldzha Municipality, Yambol Province, south-eastern Bulgaria.

According to Alexiad by Anna Komnene, the Byzantine emperor Alexios I Komnenos (r. 1081–1118) spent 40 days in the fortress during his war with the Pechenegs in 1088.

In 1186, the Bulgarian and Cuman forces of the brothers Asen and Peter engaged the troops of Byzantine emperor Isaac II Angelos, who were retreating to the fortress of Lardea amidst an anti-Bulgarian campaign.

The fortress became part of the enlarged Despotate of Kran, which served as the appanage of Aldimir, a Bulgarian noble loyal to his nephew Theodore Svetoslav.

[4] However, the fortress was lost once again during the interregnum after the premature death of Theodore Svetoslav's son George II Terter in 1322.