Catherine Zeta-Jones and Michael Douglas removed their kids ''from the crazy world of Hollywood'' to ensure they remained grounded.

The 49-year-old actress and Michael, 74 - who have kids Carys, 15, and Dylan, 18, together - have made a conscious effort to make sure their children don't get carried away by the glitz and glamour that surrounds them.

Catherine told 'Entertainment Tonight': ''They've kinda been removed from the crazy world of Hollywood or even the crazy world of Manhattan.

''The teenagers here in Manhattan, there's a maturity that comes too quick I think.''

The Welsh actress praised the maturity of her children, but she also admitted there's an element of luck involved with parenting.

She said: ''We've kind of shielded them away, but they're incredibly mature for their tender years. They get it, and that's just a thing [where] I think that I just got lucky.''

Meanwhile, Catherine recently revealed she has a ''very open'' relationship with her husband.

The actress claimed that the secret to her long-standing romance with the Hollywood icon is that they are both very ''open and honest''.

She said: ''Both Michael and I have a very open relationship. When you have kids that didn't ask to be born into a world where [the marriage is] scrutinised or looked into, you've got to be open and honest and share things that probably people at the drug store wouldn't share over the counter.''

Despite this, Catherine confessed things aren't always ''rosy'' in their love life.

She explained: ''First of all, I'm so happy that we've made it to be 20 years together. It's been great.

''But I think it's just unfathomable to me that you would be with one person for 18 years and things are not rosy every day. You know? They're just not.''