This paper describes several examples of ancient ingenuity in geo-engineering of heritage structures in Asia with relationship with authenticity. The authenticity and integrity is key factors to identify “Heritage Structure.” Wooden pillar upon foundation stone was used for ancient shrine and has been repaired partially or replaced in the past 800years in Japan. Wooden short piles beneath raft foundation in soft soil that was driven under water level are found in good condition in Japan and China. Masonry structure was used as pier for wooden arch bridge in Japan. Densely compacted soil mound played as a major component of structures in Angkor. Soils with different grain size distribution were used according to their characters of strength or permeability. However, environmental condition of monsoon has brought horizontal widening or horizontal spreading, a special type of deformations to the masonry structures in Angkor.