The ancient fortress of Brześć is at the confluence of Muchawiec and Bug Rivers. Occupying the site of a medieval castle, it was strengthened and reconstructed in Napoleonic times and then again in 1847. Heavily damaged during World War I, the fortress was turned into a matériel depot and its central part into a prison. Although largely obsolete by contemporary standards, the fortress occupied a strategic position in the Polish lines and its defence could prevent German forces from crossing Polesia into Lesser Poland and Galicia to the south.