A blaze that erupted Monday night completely destroyed the domed roof of the 18th-century Naryshkin estate in western Moscow, Russian media reported.
The two-story building located in Filyovsky Park has been undergoing reconstruction work.
Although firefighters reported that the blaze was fully extinguished by Tuesday morning, the cause of the fire has not yet been determined.
The building was constructed by nobleman Alexander Naryshkin, who for 20 years served as director of the Russian Empire's royal theaters and became famous for his extravagant parties. The estate remained in his family for 175 years.