Maguk, previously known as Barramundi Gorge, is located within Kakadu National Park.
The turn off is about 50 km from the Southern entrance and 92 km south of the Bowali Visitor Centre. The road to Maguk is actually an unsealed corrugated track mainly only suitable for four wheel drive vehicles. A word of advice, although some people may say you can get in there during dry season in a two wheel drive vehicle I wouldn't recommend it after being there myself. What's more do not attempt to take any rental vehicles down such tracks in Kakadu as you are actually breaching your rental contract. Book yourself a professional tour whether that be a complete one of Kakadu or day trips to specific areas. That was you can tour the trickier areas of Kakadu efficiently and safely as well as get the opportunity to access some more obscure locations and access their wealth of knowledge along the way.
Although more recently dubbed Maguk, an Aboriginal name, Barramundi Gorge doesn't have many if any Barramundi and doesn't look like a Gorge. Instead, as you set off on a 2km walk from the carpark you will be led through a monsoonal forest dense with vegetation and fauna. there are plenty of Crocodiles at Maguk, however, the local authorities do implement Crocodile management strategies and Saltwater Crocs are caught at the end of wet season and relocated.
As the walk continues the level of difficulty rises. With a rocky climb up to the swimming holes. I assure you,however, the walk is worth it. Take decent shoes as well as your bathers as at the top you can carefully scale down to a picturesque swimming hole. You can even continue climbing to the top of the falls.