Ostrog Synagogue - one of the oldest in Eastern Europe, Ukraine has remained such units. The plate of the Ukrainian SSR, it was reported that the building is an architectural monument, reports that it has built in the 15th c. For sure it is not known, but it is known that in the early 17th century, during the life of the educator - Talmudist Shmuel Eydelsa, it already existed. 

In Ostrog synagogue - an amazing story. In 1648 and 1649, she witnessed pogroms arranged troops Bohdan Khmelnytsky. As reported by Jewish sources of the time, neighboring wells were then filled with the corpses of Jewish children. In 1792, the synagogue where Jews hid Ostroz'ki stormed the Russian troops led by General Mikhail Kakhovskii. The Russians took the building for the fortress in which entrenched Poles and fired its cannons. According to legend, was miraculously saved Jews. Even those kernels that have flown into the building through the broken windows, no harm is inside people. On the third day of the attack on behalf of the local brave Eliezer came out of the synagogue, and showed the king's troops ford across the river Neris, then went away from the Jail. In memory of this event in the wall of the synagogue did not render over traces of nuclei, and one of the cores hung inside the building chain. There is even a legend that this was a golden chain.

http://blogs.pravda.com.ua/authors/ihelzon/4a4b78d60abab/