The site includes landscaped and manicured gardens, with meandering paths winding around the spring-fed lakes and gardens and along the river bank. More than 4,500 trees and shrubs have been planted.
At least 106 bird species have been spotted at Pallington including osprey and Cetti's warbler, as well as otters and water vole.
Pallington Lakes has become a popular tourist attraction since it opened in 2011 with over 10,000 visitors last year. It is expected to sell for around £2m although sculptures are not included.
Gudgeon said the site's growing popularity had led to increasing amounts of administration which was hampering his work as a sculptor.
"Creating Sculpture by the Lakes has been an achievement that my wife Monique and I are immensely proud of. We are of course sad to be selling the sculpture park but very much hope that the new owners will continue to run it as it is.
"From the first day we opened in June 2011, the response from visitors has been nothing but enthusiastic and Sculpture by the Lakes now has a loyal and ever increasing band of followers. It has become a place that thousands of people from all over the world have fallen in love with."