Rotary Botanical Gardens was established in 1988 by Janesville Rotary Clubs on the grounds of a defunct sand and gravel quarry. The 20-acre site contains a number of themed gardens, including Japanese, Scottish, French formal, Italian, and English cottage gardens.
The Japanese garden borders a pond that is spanned by a red Japanese-styled bridge.
A sunken garden is surrounded by limestone walls and perennial plantings. Its entrance is a Tudor-style stone arch that was once the entrance to the Parker Pen Company's world headquarters formerly located in Janesville.
There are also less formal gardens, such as a fern and moss garden, and shade, prairie, and woodland gardens.
Rotary Botanical Gardens hosts an annual themed Garden Art Project Exhibit, showcasing the work of local artists.