The Wildlife Heritage Foundation (perhaps more commonly known as the Big Cat Sanctuary) is situated near Smarden in Kent. They are dedicated to the captive breeding of endangered big cats. You can find out more about the WHF and what they do on their website. The sanctuary is not open to the public, but during the year they offer a limited number of 10 person, 4 person and individual photographic workshops, I opted for the 4 person workshop as a nice balance between the cost of the individual workshop and the less personal nature of the 10 person workshop (where non photographing guests are also welcome).
As you can see from the photos, access is amazing. I was nervous about just having 140mm (210mm full frame equivalent) at my disposal, even though they insisted 200mm was more than enough beforehand, but it was absolutely fine.
Fuji X-T1, Fujinon 50-140mm 2.8