Shamakhy Astrophysical Observatory is an observatory in the Caucasus Mountains in Azerbaijan. It is named after Nasreddin Tusi (Shao) (Nəsirəddin Tusi adına Şamaxı Astrofizika Rəsədxanası). It is located on the eastern slope of Pirqulu, at an elevation of 1500 m. It has 150-200 clear, cloudless nights per year.