The Sidabrė mound is a unique historical site of the old Semigallia. In the XIII century the Castle of Sidabre was standing there. The castle was mentioned in written records in 1288 for the first time. Joniškis, titled as a Lithuanian capital of Semigallia, links its origins with this date and place. This place has inspired the people of Joniškis to the events of the Lithuanian National Revival. The monument dedicated to the Castle of Sidabrė, to the memory of Semigallians, bear witness to the events of Revival.