What is the geographical feature characterized as a hilly region that crosses the middle part of Georgia?

The Piedmont region is indeed the correct answer as it is defined by its distinct hilly terrain and lies between the coastal plain to the south and the mountains to the north. This area is characterized by rolling hills and a series of ridges and valleys, making it a unique geographical feature of Georgia. The region serves as a transition zone from the flat, low-lying coastal plains to the mountainous areas farther north, offering a diverse landscape that includes both urban and rural areas. The Piedmont is not only significant for its topography but also plays a crucial role in the state's economy and culture.