Hilly doesn't necessarily mean the hills are big; it focuses more on the quantity. Even with many small hills, the park is considered a hilly landscape.
Pro Tip 2/3
Conveys Difficulty
Hilly suggests challenge in activities like cycling or walking due to constant changes in elevation. I prefer cycling on flat roads because hilly routes can be exhausting.
Pro Tip 3/3
Descriptive Imagery
Using 'hilly' helps readers imagine a landscape's appearance and feel its ups and downs. Her painting perfectly captured the hilly countryside's beauty.