LT2006 m. rugpjūčio mėnesį vykdyti žvalgomieji archeologiniai tyrimai numatomo įrengti pramoninio lauko vandentiekio trasos vietoje, Astravo buvusio dvaro sodyboje (G 260K) (Biržų r.) [p. 205].
ENIn 2006, 9 evaluation test pits were excavated on the grounds of Astravas estate (Biržai Dist.), which was built in the 19th century. The remains of buildings and a former pond were discovered.