Material biography and technical utility of 8th-century wooden garden infrastructure: evidence of timber reuse in Unified Silla, Korea

Waterlogged wooden structures from royal garden contexts provide rare evidence of ancient landscape management and woodworking practices. This study investigates eleven wooden elements excavated from Wolji Pond, a royal garden of the Unified Silla Kingdom (eighth century CE), to evaluate possible timber reuse within aquatic installations. A multi-analytical workflow combining morphological reassessment, digital radiography, wood anatomical analysis, and micro-XRF was applied. The results identified two coherent wooden lattice assemblages characterized by differentiated structural elements and concealed internal cavity features. Surface planing tool marks and localized iron-rich red pigment residues indicate earlier phases of timber processing prior to final deposition. Wood anatomical analysis identified all elements as hard pine ( Pinus spp.). These observations suggest that some lattice elements may have undergone multiple stages of modification and reuse before incorporation into the pond landscape. The study demonstrates the value of integrated archaeometric approaches for investigating waterlogged wooden heritage.