Amazon Studios and Bleecker Street released the first official-trailer for “The Lost City of Z,” which is set to open in New York and Los Angeles in April. The film, which was written and directed by James Gray, is based on the book: “The Lost City of Z: A Tale of Deadly Obsession in the Amazon” by David Grann.

Starring in the film are Charlie Hunnam, Robert Pattinson and Sienna Miller, they will be joined by Tom Holland and Angus Macfadyen. The film aims to tell the true story of British explorer Percy Fawcett (Charlie Hunnam), who journeys into the Amazon at the dawn of the 20th century and discovers evidence of a previously unknown, advanced civilization that may have once inhabited the region.

Despite being ridiculed by the scientific establishment who regard indigenous populations as “savages,” the determined Fawcett – supported by his devoted wife (Sienna Miller), son (Tom Holland) and aide-de-camp (Robert Pattinson) – returns time and again to his beloved jungle in an attempt to prove his case, culminating in his mysterious disappearance in 1925.

The studio describes the film stating, “An epically scaled tale of courage and obsession, told in James Gray’s classic filmmaking style, “The Lost City of Z” is a stirring tribute to the exploratory spirit and those individuals driven to achieve greatness at any cost.” Explorers can watch the first trailer-below, or on the official ” target=”_blank”>Amazon Studios YouTube page.

Bleeker and Amazon Studios released a teaser trailer for the film earlier this year, but this marks the first full-length trailer for the film. After the two-city premiere of “The Lost City of Z,” the film is set to open nationwide on April 21, 2017.

Charlie Hunnam will also be starring in “King Arthur: Legend of the Sword,” directed by Guy Ritchie. Hunnam is set to take the title lead in that film, and the studio released a teaser-trailer for the project last month. Guy Ritchie and Joby Harold wrote the screenplay for that film, which also stars Hermione Corfield, Katie McGrath, Jude Law and Eric Bana.