Conjoined twin sisters attached at the head

Conjoined twins, Neev and Nelly Kolestein, have been attached by the back of their heads for 18 years – but that hasn't stopped their determination to change the way people view disability.

Despite only ever seeing each other through a reflection in a mirror, Neev and Nelly have formed an unbreakable bond and admit they would never want to be separated from each other.

As Craniopagus twins, the girls are a medical phenomenon; representing just two to six percent of conjoined twins worldwide, they are the rarest form.

Doctors didn't think they would survive birth, and if they did, they predicted they would live a poor standard of life until they reached 10 years old.

Proving all the odds wrong, Neev and Nelly are still thriving as 18-year-old girls, who can never be separated due to sharing an important vein in the head.

Living in Amsterdam, Netherlands, they have now started their own YouTube channel and Instagram page, aiming to raise awareness of their condition.