The Gothic Church of St Nicholas is famous for hosting Brandenburg’s first public Lutheran-style service back in 1539, under elector Joachim II, whose bronze statue stands outside the church. Inside, treasures include a baptismal font (1398), a baroque pulpit (1714) and an 8m-high late-Renaissance altar (1582).
Also note the cannonball lodged in the northern church wall that commemorates the attack on the Spandau citadel in 1813.