Question: How many acres is the Disney's Animal Kingdom themed area featuring the Na'vi River Journey?

Context paragraphs:
Thomas Land (Drayton Manor): Thomas Land is a themed area at Drayton Manor Theme Park in Staffordshire, England, based on the TV series "Thomas and Friends".  It stands on the former site of Robinsons Land, a themed area sponsored by the soft drinks brand of the same name.  The construction began while the park was still open in September 2007, and many of the Robinsons Land rides were moved to other areas of the park for the remainder of the season.  Many of the rides housed in Robinsons Land except the Veteran Cars (now Sodor's Classic Cars) were sold to Funland in Hayling Island.  Thomas Land officially opened to the public on 15 March 2008.  An expansion of Thomas Land with additional attractions and private party rooms opened on 8 April 2015.

2011 Souris River flood: The 2011 Souris River flood was greater than the hundred-year flooding event for the Souris.  The US Army Corps of Engineers estimated the flood to have a recurrence interval between 200 and 500 years.  The Souris River is a tributary of the Assiniboine River, which it meets near Treesbank, Manitoba.  The Assiniboine meets the Red River of the North in Winnipeg, Manitoba.  The flooding has affected Saskatchewan and North Dakota, and overtopped levees in Minot, North Dakota causing the evacuation of about 11,000 residents.  The flooding in Minot was worse than the 1969 flood and 1881 flood.  Many other towns along the river were affected and many acres of farmland were inundated.

Disney's Animal Kingdom: Disney's Animal Kingdom is a zoological theme park at the Walt Disney World Resort in Bay Lake, Florida, near Orlando.  Owned and operated by The Walt Disney Company through its Parks and Resorts division, it is the largest theme park in the world, covering 580 acres .  The park opened on Earth Day, April 22, 1998, and was the fourth theme park built at Walt Disney World.  The park is dedicated and themed entirely around the natural environment and animal conservation, a philosophy once pioneered by Walt Disney.

Na'vi River Journey: Na'vi River Journey is a dark ride attraction at Disney's Animal Kingdom's Pandora – The World of "Avatar".  The ride takes guests through the Kasvapan River of Pandora from the 2009 film "Avatar", showcasing native animals and bioluminescent flora, with inclusion of Audio-animatronics.

Maharajah Jungle Trek: The Maharajah Jungle Trek is a themed wildlife trail attraction at Disney's Animal Kingdom theme park at the Walt Disney World Resort in Lake Buena Vista, Florida.  It is in the Asia themed land, the Kingdom of Anandapur.  It shares this area with the Kali River Rapids white water raft ride and the Expedition Everest runaway train rollercoaster.

Kennyland: Kennyland was a themed area at the Dreamworld theme park on the Gold Coast, Australia.  It was an area featuring a variety of children's attractions from 1999 until 2002 at which time it was replaced with a larger Nickelodeon-themed area called Nickelodeon Central.

Star Wars: Galaxy's Edge: "Star Wars": Galaxy's Edge is an upcoming "Star Wars"-themed area being developed at Disneyland Park at the Disneyland Resort in Anaheim, California and Disney's Hollywood Studios at Walt Disney World in Bay Lake, Florida.  The "Star Wars"-themed area, or "land," at each park will encompass 14 acres.

Kali River Rapids: Kali River Rapids is a river rapids ride at the Disney's Animal Kingdom theme park of the Walt Disney World resort, in the "Asia" area.  It is themed as a rafting expedition along the Chakranadi River, courtesy of "Kali Rapids Expeditions".  In keeping with Disney's Animal Kingdom's message of conservation and environmental protection, this attraction deals with illegal logging and habitat destruction.

Pandora – The World of Avatar: Pandora – The World of "Avatar" is a themed area inspired by James Cameron's "Avatar", located within Disney's Animal Kingdom theme park at the Walt Disney World Resort in Bay Lake, Florida, near Orlando.  Set a generation after the events of the "Avatar" films, the area is based upon the fictional exoplanetary moon, Pandora, and features Pandora's floating mountains, alien wildlife, and bioluminescent plants.  Spanning 12 acres , Pandora – The World of "Avatar" includes two major attractions, "Avatar" Flight of Passage and Na'vi River Journey, as well as retail and dining outlets.

Wildlife Express Train: The Wildlife Express Train is a narrow gauge rail transport attraction at Disney's Animal Kingdom in Walt Disney World.  It’s route is 1.2 mi long and takes guests from Harambe Station in the Africa section to Conservation Station in the Rafiki's Planet Watch section.  During the ride, portions of the Animal Kingdom backlot can be seen, including animal holding buildings for rhinos and elephants, among other animals as well as the roundhouse where the trains are stored.  It takes about seven minutes to go from Harambe Station to Conservation Station and an additional five minutes to return.  The railway is built to a narrow gauge, which is smaller than the currently used on East African railways.  The full journey is a 1.2 mi round trip.

Supporting paragraphs: Pandora – The World of Avatar Na'vi River Journey
Answer: 12 acres