"The Suwon Dulle Gil (Suwon Perimeter Trail) is a 65 kilometer trail that roughly follows the borders of the city of Suwon. The route is about 35 kilometers through the hills in the north and west of the city, about 5 kilometers though some pleasant parks in the east, and about 25 kilometers of city running. It’s a nice tour. You don’t need to start with much water, as there are a ton of convenience stores whenever you enter a city part, or reach the bottom of a mountain. The highest peak is 582 meters. There are some maps along the trail which state that the entire route is 60 kilometers. They are incorrect." (from https://www.toeflresources.com/running-the-suwon-dulle-gil/, which includes further details about the route)
The highlights include Wangsong Lake, Mt. Gwanggyosan, Gwanggyo Lake Park, Suwon Air Base, and Mt. Chilbosan.