Hannover has had better luck attracting trade-show visitors than tourists, although the fairgrounds and the futuristic country pavilions left over from Expo 2000 (the World's Fair) have seen better days. An older attraction is the Herrenhausen Gardens. It has intricate flowerbed patterns, one of the largest garden fountains in Europe and the Regenwaldhaus, a large greenhouse with rain-forest plants.
Most of Hannover's old city was destroyed in World War II, replaced now by new German architecture. However, the Marktkirche, a Gothic-style church in brick, and the Altes Rathaus (Old Town Hall) were reconstructed after the war. You'll also probably notice some interesting bus and tram stops: The city invited international artists to design them. Nearly 60% of the city is preserved as parkland or forest today. The Maschpark near the new town hall and the artificial lake called Maschsee are nice recreational areas. Excursions from Hannover could include
Celle, a beautiful town of half-timbered houses with one of North Germany's most important medieval monasteries nearby, or
Hameln, of Pied Piper fame.
150 mi/250 km west of Berlin.