I didn’t realize how few films like “The Lost City of Z” there are until I watched it. It’s not an action film, but it certainly has more action than most dramas. It’s an adventure film based on a true story of Percy Fawcett, an early 20th century British explorer determined to find proof of the advanced civilization he is convinced once existed in the heart of the Amazon.

Whether he’s facing down piranhas while abroad or snooty British scientists scoffing at “inferior” races back at home, Charlie Hunnam commands the screen as Fawcett, especially because he is no superman explorer. We learn right away that, while he is a skilled soldier, he is still desperate for advancement, and his career is at a deficit because of the shame his alcoholic father brought on the family name. Self-interest, not heroics, launches his first journey to the Amazon.

Joined by his aide-de-camp Henry Costin (a great character role for Robert Pattinson, who is finally moving away from his glittery vampire past), Fawcett and his small team make a treacherous journey down the Amazon, strongly recalling “Heart of Darkness” and “Apocalypse Now.” He is just there on a surveying mission, but clues to an advanced civilization described by his guide haunt him once he returns to England.

“The Lost City of Z” is a richly detailed, carefully paced story, and it is also very beautiful and atmospheric. A sense of authenticity pervades all the settings and all the characters, as appropriate to a fabulous and legendary but also true story. Based on the 2009 book of the same name by New Yorker writer David Grann, the period details are fully realized but never overpower the story.

As Fawcett’s intellectual wife, Sienna Miller gets to do more onscreen than usual, ably but grudgingly keeping the home fires burning for the years Fawcett is gone. The aforementioned pace of this somewhat lengthy film allows for ample character background and development, creating a strong foundation for the many action sequences. This includes not just jungle expeditions, but trench warfare in World War I.

There are many issues of colonialism and racism inherent in a film about white British explorers in a nation not their own, and the film presents the story without demonizing or lionizing Fawcett. His thoughts on these subjects are complex and flawed; he is more enlightened and sympathetic than many of his countrymen, but he is also out to make a name for himself and his family.

His family, too, is another source of complexity in the film. He discusses equality with his wife, but she clearly points out how far short of that they fall. He anguishes over leaving his family, but does so anyway. Eventually his son grows up and accompanies him on his final expedition, consigned with his father to an unknown fate in the lush jungle.

“The Lost City of Z” is a rather glorious adventure tale, almost in the vein of “Indiana Jones” without the humor. It is old fashioned in the best sense, full of pith helmets, piranhas, compasses and mystical gold glittering in the mist.

“The Lost City of Z” is currently available to rent.