Wildlife and theme parks
This is, allegedly, the only place in the world where you can visit a colony of nesting Mute Swans. (Trust me, they are not mute). A Benedictine monastery was established at Abbotsbury in the 11th century and the monks began farming swans - which often featured at medieval banquets. The monks have long gone, but the swans are still there (different ones, obviously). If you visit Abbotsbury Swannery these days, you'll find about 600 swans, all free to roam. The colony is established adjacent to a shallow lagoon, the Fleet, which lies behind Chesil Beach. It's a unique location.
The seat of the Duncombe family since 1711, when the house was built by Thomas Duncombe (born Thomas Browne). His descendent, Charles Duncombe, was created Lord Feversham in 1826. The house is not open to the public, but 450 acres of parkland, gardens and nature reserve are. There is also a bird of prey centre on site.
One of probably hundreds of open farms in the UK, primarily aimed at children. Greenlands has all the farm animals you would expect, plus some you wouldn't, such as deer, a chameleon, an owl, a snake and alpacas. There are a couple of great slides, plus a good indoor play area, as well as various shops and a cafe - and picnic tables.
One of Britain's largest colonies of common and grey seals is at Blakeney Pont, a 4 mile spit that sticks out into the North Sea. It is a national nature reserve, and a favourite spot for birds, native and foreign, as well as seals. Various companies run boat trips to see the seals. The trips last about an hour and tend to depart from Morston Quay.
The link below will take you to one operator - but there are others - no recommendation is implied.
What used to be South Lakes Wildlife Park opened to the public on a fairly wind-swept location in 1994 and has more than 1,000 animals in its care, including large cats and mammals, primates, reptiles and birds. Some animals roam wild - so you can walk among kangaroos and emus. There are aerial walkways over some enclosures, giving astonishing views. The zoo boasts a proud track record in conservation. Unfortunately, it has a chequered safety history, including several animal escapes, a fire in which 30 lemurs died and the death of a keeper, mauled by a Sumatran tiger, in 2013.
NOTICE - As of 6 March 2017, the future of this attraction looks uncertain. Check the zoo's website for up to date information.