Douglas Booth and Logan Lerman have revealed they bonded like real brothers while filming Noah.
The 21-year-old Romeo And Juliet heartthrob and the 22-year-old Percy Jackson star play Noah's sons in Darren Aronofsky's biblical epic.
Douglas revealed: "We get on really well and we hung out a lot, so it was pretty easy to create that sort of brotherly experience in the film, although we weren't as close on screen.
"We went hiking in Iceland, just the two of us, up Mount Esja near Reykjavik. We went to a Jay Z concert in New York, plenty of dinners and nights out.
"We went to the Blue Lagoon (in Iceland) which we didn't like.
Logan added: "Did not like it. Tourist trap."
The young actors admitted working on the film - which has attracted controversy among religious audiences - was pretty intense.
Logan revealed: "Between takes there wasn't a ton of laughs but between working days we had a ton of fun."
And they also revealed Russell Crowe, who plays hero Noah, was scarier in real life than Ray Winstone, who plays the villain Tubal-Cain.
Logan said: "Russell is definitely more scary. Ray is not a very scary guy, he seems scary, he looks scary, but he's the nicest dude."
Douglas added: "He can be scary but he's one of the nicest men you'll ever meet in your life."