A RANDY foursome were caught romping in broad daylight as children played at a nearby castle.

Stunned onlookers watched as the amorous group brazenly enjoyed an orgy on grass at Cardiff Castle.

One of the women bared all as the two couples got carried away with their x-rated display at around 5pm on Friday.

A shocked witness snapped photos of the foursome's steamy sex session after mistakenly believing they were enjoying a leisurely picnic in the sunshine.

The bystander said: "It looked as though one of the women was scratching her crotch quite a lot. So, I looked a little closer and I realised what she was actually doing."

They then watched on in horror as one of the men whipped his todger out as one of the women engaged in what appeared to be sexual activity with another female.

The witness explained: "It then clicked that something very strange was going on.

"I felt like a rabbit in the headlights - I was frozen and couldn't stop watching."

The onlooker told a cop about the outdoor romp as there "plenty of children" around.

They were gobsmacked when they went back and saw the group having "full on sex" in Bute Park in the city centre.

South Wales Police have been made aware of the incident and are asking for anyone with information to call 101.

Cardiff Council who manage Bute Park says it is aware of the incident and it's now with the police.