The round Gromovaya (Thunder) Tower with its pretty wooden roof stands alone and houses the 'Smolensk - Shield of Russia' Museum which has exhibits on Smolensk's military past. The second tier of the tower has displays on the building of the Smolensk Cathedral. The third tier has an exhibit on the Battle of Grunwald, where soldiers from Smolensk took part in the Grand Duchy of Lithuania's defeat of the Teutonic Knights. The fourth tier comprises a viewing platform. The museum is run as part of the Smolensk State Museum-Reserve.