I spent a couple of days in Lincolnshire last November / December time (was around the UAE GP time) and I visited Ark and had a good chat with the gentleman who owns the place. (His wife makes amazing homemade food in the cafe, the cakes were lovely).
They are effectively a rescue centre and all their animals are rescues or former pets. They had a few good reptiles as well, and a Morelets Crocodile in its own small exhibit.
The collection is very small but space is also limited. Trying to find the place is a nightmare as there are no sign posts on any of the main roads and it is pretty much in the back of a housing estate.
There were a lot of domestics there, but also a few cool smaller animals like a Kinkajou, Palm Civet and Jaguarundi's (One with only 3 legs).
The owner was saying last November they were building a larger area to the side of the park as they were in talks about getting a pair of rescue Wolves from somewhere but I don't know if anything had come of that.
It was a small place which took no more than 45/60 minutes to go round, but it's close to Woodside and also the Seal Sanctuary so you could easily pair it with another place and make a day of it.
A wouldn't really say it's a collection to watch though, as it's very small, a bit farmy and no real space to expand and it is mainly domestics and reptiles. All the animals are rescues so it's unlikely they will ever get any bigger attractions and it is certainly not big enough to have any large Zoo type animals.
The Lynx they had there was a pet of the owners who he had, had since she was a kitten and she was very voice responsive to the owner, she looked pretty much tame !