Nicole Kidman celebrates 18th wedding anniversary with Keith Urban with sweet snap of the pair: 'Forever'

Nicole Kidman marked her 18th wedding anniversary with husband Keith Urban in a sweet Instagram post on Tuesday.

The Oscar-winner, 57, and the singer, 56, who recently opened up about nearly destroying his marriage due to alcoholism, posed up in a scenic snap to mark their anniversary,

In the photo a barefoot Nicole flashed her legs in a summer dress as she lay her head on a brick wall overlooking the sea, while Keith strummed a guitar next to her.

She captioned the post: 'Forever. #happyanniversary.'

Actress and Nicole's BFF Naomi Watts commented: 'This looks like true love, heavenly' while Tom Hanks' wife Rita Wilson penned: 'Love you both. Happy Anniversary, lovers.'

Nicole Kidman marked her 18th wedding anniversary with husband Keith Urban in a sweet Instagram post on Tuesday

Last week Urban stunned an A-list crowd by very publicly admitting how he once almost destroyed his marriage with Nicole Kidman.

The Australian country singer was presenting at the AFI Life Achievement Award Gala Tribute to Nicole Kidman, when he made the shocking confession.

The ceremony was a private event held in Los Angeles on Saturday, April 26, and it was finally broadcast on television earlier this week.

'We got married in 2006, and barely four months into our marriage, the addictions that I had done really nothing about blew our marriage to smithereens,' he began. 

Urban revealed that he was struggling with addiction when he first met Nicole and with her support he managed to eventually pull through. 

'Four months into a marriage, and I'm in rehab for three months with no idea what was going to happen to us.

'Nic pushed through every negative voice - I'm sure even some of her own - and she chose love.

'And here we are tonight 18 years later. Her capacity to love is like no one I've ever met.'

Upon listening to her husband's emotional speech, Kidman was seen in the audience wiping a tear from her eye as she took in his heartfelt words.

The pair tied the knot in 2006 and are parents to daughters Sunday Rose, 15, and Faith, 13 - pictured April

Naomi Watts and Rita Wilson sent their well-wishes on the day 

In April  Urban stunned an A-list crowd while paying tribute to Nicole  by revealing how he almost destroyed their marriage.

Urban revealed that he was struggling with addiction when he first met Nicole and with her support he managed to pull through. Upon listening to her husband's emotional speech, Kidman was seen in the audience wiping a tear from her eye as she took in his heartfelt words

The star was wed to Tom Cruise from 1990-2001 - pictured 1999 - they share two children

The father-of-two, whose previously said he grew up watching his father's heavy drinking, previously said it took him 'a long time to get sober' because he didn't 'recognize' his alcoholism.

The pair tied the knot in 2006 and are parents to daughters Sunday Rose, 15, and Faith, 13.

She also shares an adopted daughter Isabella, 31, and son Connor, 29, with ex-husband Tom Cruise.