Abstract: Lake Köyceğiz, at Southwest Anatolia, is natural coastal dam lake that have two basins and is connectedto Mediterranean via a natural channel called Dalyan. In the scope of this study, two of the four short (max 800 mm)gravity cores were recovered from Köyceğiz Basin (north of the lake), one from Sultaniye Basin (south of the lake)andone core from the ridge between these two basins. Recovered cores are lithologically described and cores are analyzedfor multi-element geochemical analyses at 5 mm resolution using µXRF core scanner (ITRAX) and Multi Sensor CoreLogger (MSCL) for Magnetic Susceptibility. Cyprideis torosa (ostracoda) shells were picked and analyzed for 18O andδ13C analysis at 20 mm resolution. The cores were dated through AMS 14C analysis of various shells. The results ofAMS 14C analysis are corrected by assuming the hard water/local reservoir ages effect as 2100±90 years; accordingto the sedimentation rates from previous studies and known hard water/reservoir effects in Mediterranean lagoons.According to the age models, the cores span approximately last 500 years. Multi-proxy results suggest that LakeKöyceğiz cores cover Little Ice Age and show good correlation with decreases in Solar Activity spells, namely, Spörer,Maunder and Dalton Miniumum. These periods are characterized as cold/dry periods in Lake Köyceğiz sedimentrecords. So we can say that, climate of the region depends on the variability of sunspot numbers.