Located in the southeastern part of the peninsula, Gyeongsang-do is home to the former capital of the Shilla Dynasty, Gyeongju, as well as the country's largest port, Busan.
Most of this region is made up of the large basin created by the Nakdong River and is surrounded by the Sobaek and Taebaek mountain ranges. The topography of the land has created distinct and isolated subcultures, causing the people to have a strong dialect and giving rise to customs unique to the area. Although you'll notice regional accents outside of Seoul, even native South Koreans grouse that Gyeongsang-do dialects are difficult to understand.
Rapid industrialization has laid waste to some of the quiet scenic beauty of the region, but pockets of a slower time still remain. You can experience the largest and best-preserved traditional village in the country in Andong. Of course, you don't want to miss Gyeongju, with its historic temples and small-town charm. For really old relics (as in prehistoric), make a special trip to Goseong to see the former nesting grounds of dinosaurs and the footprints they've left on the rocky coast. While you're in the area, take a detour to Tongyeong, which I think is the most dramatically beautiful coastal town in the country. Other points along the southern coast are also great for seeing oceanside scenery and some of the natural beauty of South Korea.
Summers are hot and humid. Areas inland, isolated by the mountains, are hotter than the rest of the peninsula, so the expansive sandy beaches in the southern and eastern coasts draw thousands of people escaping the heat of the cities. The region is famous for its salty and spicy cooking. Although the dishes are not as refined as those from Jeolla-do or the Seoul area, the ingredients are always fresh and seafood abounds from both the southern and eastern coasts.