Kung Fu Panda 2 kicked the UK Box Office's ass this week, taking £6.19m in its first weekend.

That's a massive relief for everyone who thought that The Hangover Part II might grab hold of the top spot, proving that there's nothing as satisfying as seeing an overweight panda punch Bradley Cooper in the face.

Yes, that figure includes previews and 3D ticket prices, but it's still officially a step up from the first Kung Fu Panda, which opened on £6m, so DreamWorks will be fairly chuffed to see their chubby dragon warrior bringing in the kids. With Rio finally down at number ten in the UK charts, expect the Kung Fu Panda to stick around well into the summer holidays.

The Hangover 2 is still terrifyingly successful in second place. It dropped 28% to take under £3m in its third week, but is now on a total of over £26m. Warner Bros will be laughing.

If Werner Herzog hasn't been there, it ain't a cave.

It's hard not to think that after gazing in wonder at Cave of Forgotten Dreams, Werner's 3D tour of South France's Chauvet caves. It's a completely unique experience. Even more unique than Bad Lieutenant: Port of Call - New Orleans (and yes, lizards feature in both).

But as amazing as Germans, 32,000 year old porn and "scientists" playing the flute are, there are other places you can go to get your cavern-based kicks.

Speaking of which, here are some of cinema's best caves...

Director: Werner Herzog
Cast: Werner Herzog, Jean-Michel Geneste
Certificate: U
Trailer

Imagine you’re in a cave. That’s it. That’s the experience you get from Werner Herzog’s 3D documentary. 90 minutes of standing in a cave. With tons of prehistoric drawings to keep you company. And Werner Herzog, of course.

Director: Jon Chu
Cast: Justin Bieber
Certificate: U
Trailer/Clips

"I LOVE JUSTIN BIEBER!" "I LOVE HOW HE LOOKS!" "OH MY GOD, I LOVE HIS HAIR!" "JUSTIN!! JUSTIN!!" Two hours of screaming fangirls and devoted teenyboppers is no-one's idea of a good time. But you know what? Justin Bieber: Never Say Never 3D actually is a good time. Maybe it's The Bieber's raw charisma, or his annoying musical talent, but this concert movie is solid, straight-up fun. I blame the hair.

Directors: Henry Joost, Ariel Schulman
Certificate: 12A

When people first heard of a Facebook movie, this is the kind of thing they imagined instead of David Fincher's award-friendly drama. But even they couldn't have expected such an unsettling and poignant piece of cinema.

Director: Michel Gondry
Cast: Michel Gondry, Suzette Gondry
Certificate: PG

Have you ever made a film about your Aunt Suzette? Michel Gondry has. Why should you care? Maybe you don’t like watching other people’s home movies. Maybe you don’t even have an Aunt Suzette. Watching The Thorn in the Heart won’t change either of those very much.

Directors: Henry Joost, Ariel Schulman
Showtimes

When people first heard of a Facebook movie, this is the kind of thing they imagined instead of The Social Network. But even they couldn't have expected such an unsettling and poignant piece of cinema.

Following the revelations about I'm Still Here, Joaquin Phoenix went back on the Late Show with David Letterman this week.

Apologising to Letterman for his appearance in-character on the show during the filming of Casey Affleck's mockumentary, Joaquin attempted to clear the air:

"You’ve interviewed many, many people and I assumed that you would know the difference between a character and a real person, so… but I apologize… I hope I didn’t offend you in any way."

Explaining that Letterman was not in on the film's hoax, Joaquin Phoenix answered the host's questions about how they both came across after that interview - particularly what Phoenix and Affleck are planning to do about the 5 minutes of CBS content that appears in the film. Although his jokey demands for a payday are most likely just that.

You do wonder if the other people duped on screen will feel the same way. Then again, Joaquin has already been in talks to appear in Clint Eastwood's Hoover, so folks down in Hollywood can't be that bitter about it.

The fascinating I'm Still Here is still out in UK cinemas. Check out our review here, or read on for the second on-air encounter between Phoenix and Letterman. 

Director: Casey Affleck
Cast: Joaquin Phoenix
Certificate: 15
Trailer/Clip

Is it a hoax? That's the main discussion surrounding I'm Still Here, which purports to show the "lost year" of Joaquin Phoenix, who publicly decided to retire from Hollywood and head to hip-hop instead. Directed by his brother-in-law Casey Affleck, it's a funny, bizarre and candid look at life in the glare of the media. But it is true? Joaquin definitely did stop acting for a while. He did perform as a rapper. And he did grow a beard. The crazy part? Well, that's quite believable too.

Casey Affleck has revealed the truth behind documentary I'm Still Here. After a year of speculation from the public and the press, he's answered the question: was it all a hoax?

And to be honest, it's a shame that he's said anything beyond vague comments. The film's impact remains the same either way, but admittedly part of the fun of I'm Still Here is deciding for yourself whether it's a hoax or genuine. So be warned of a massive spoiler coming up in the next sentence.

Speaking to the New York Times, Affleck revealed that the documentary isn't a documentary at all. It's more "performance art". Calling it an attempt at "gonzo film-making", the director admitted that "virtually none" of the film was real. Except for the David Letterman part. The chat show host reportedly had no idea what was going on.

Casey went on to say that Joaquin Phoenix's performance (as himself) is "the performance of his career" - something that most people would agree on. His commitment to convincing the world that he was retiring to become a rapper was impressive. Even if his music was terrible.

"I never intended to trick anybody," Affleck added. "The idea of a quote, hoax, unquote, never entered my mind."

Of course, there's always the chance he's just blowing more smoke onto mirrors. But to focus on the issue of it being a hoax ignores the brilliance of I'm Still Here - it's still a candid exploration of the artist's identity in the glare of the media. It's raw, interesting and fascinating. Plus you get to see someone poo on Joaquin Phoenix's face.

I'm Still Here is released in cinemas today. You can check out our review over here.