Before the Second World War, the elliptical core of Hannover was a dense warren of half-timbered houses dating back to the Middle Ages — narrow lanes, poor housing and, by reputation, plenty of crime. The bombing raids of 1943 reduced almost all of it to rubble: only forty old half-timbered buildings survived, twelve of them in Knochenhauer-, Kramer- and Burgstrasse.
During reconstruction, salvaged facades from across the old town were gathered and rebuilt around this small surviving cluster, creating today's "new old town" — a compact, walkable patch of medieval atmosphere that you can cover in an hour. Hannover's oldest building, a Renaissance-fronted house from 1566, stands on upper Burgstrasse. Nearby is the Kreuzkirche (1333), the city's oldest church, with an altar by Lucas Cranach the Elder. From here it is a short walk along Kreuzstrasse to the Ballhof — a 17th-century ball-game hall later turned theatre — and the rebuilt Leibnizhaus, once home to the philosopher Gottfried Wilhelm Leibniz.