Emperor Moth Caterpillar

Found a few of these of these guys up on the hill above the Korean War memorial. Hope these are Emperor Moths!
From ukmoths page:

The Emperor moth is Britain's only resident member of the Saturniidae family. It is reasonably common over much of Britain, occupying moorland and open country.

The males, which have bright orange hindwings, fly during the daytime in search of the greyer females, which fly at night. Both sexes are on the wing in April and May.

The fully grown caterpillar is green with black hoops containing yellow wart-like spots, and feeds on moorland plants such as heather and bramble.