LumpyLand is an large amusement park that is owned, operated, and built by Lumpy. It was first seen in "The Wrong Side of the Tracks", and it was rather unsafe. In this episode the front side of the park appears to be Lumpy themed and there is many Lumpy merchandise available as souvenirs.
It was later revealed in "Dark Ride" that the park is indeed large as there are different themed areas. In this episode Snuffly was in the Adventure side of the park and went on a boat ride. This area of the park looks like a jungle and has adventure themed rides.
In both "Remain Seated" and "Dark Ride" Lumpy has made the park safer and also a bit more generic. The rides have safety instructions and in "Remain Seated" the roller coaster crash was caused by a slightly broke track (Likely from the ride being used and not checking it often enough) and also because of Gus not obeying the safety rules and standing up on the ride.