Takasaki City is 50 min from Tokyo. The city center has many shops & hotels and is a convenient travel hub. Takasaki city also includes Mt. Haruna and Lake Haruna, 40 min drive away.
Maebashi City is 70 min from Tokyo. It's an exciting art and nature city, including nearby Mt. Akagi, Lake Onuma, and more. It's also a good base to use to travel around the region.
Tomioka City is 2hours from Tokyo. It's known for its UNESCO World Heritage site Tomioka Silk Mill and its history that helped form Japan's industrialization.