A whopping 1.5 million people visited Chester Zoo in 2015 - making it the UK’s most visited paid-for attraction outside London.

Visitor numbers leapt up 18% to 1,694,115, the most in the zoo’s 85-year history.

The results have been released by the Association of Leading Visitor Attractions (ALVA).

Chester Zoo managing director Jamie Christon said 2015 was ‘massive year’ following the opening of the £40m Islands project.

He said: “It has completely transformed the way people can view animals and has proved to be a step in the right direction for highlighting the endangered species we work with out in the field across South East Asia.

Chester Zoo's huge new Islands development from above

“As a conservation and education charity, we rely solely on the income from our visitors to help us fund more than 80 conservation projects across 30 different countries.

“A huge thank you goes out to everyone that has walked through our gates as, without their visit, we couldn’t help the hundreds of threatened species in the wild.”

One-week-old Eastern black rhino calf, Gabe, steps out into the sunshine on his public debut at Chester Zoo
One-week-old Eastern black rhino calf, Gabe, steps out into the sunshine on his public debut at Chester Zoo

Islands, the biggest zoo development of all time in the UK, hosts a number of animals classed as critically endangered in the wild including Sumatran tigers, Sumatran orangutans and the cassowary bird.

As for this year, Channel 4 documentary series The Secret Life of the Zoo has given viewers a unique insight into what goes on behind the scenes.

Mr Christon said: “We’ve already had an incredibly strong start to 2016 with The Secret Life of The Zoo and the birth of a whole host of endangered species, such as an Eastern black rhino calf and baby silvery gibbon.

Viewers can experience the wonders of life at Chester Zoo in new documentary
Viewers can experience the wonders of life at Chester Zoo in new documentary

“This year will see a whole host of new visitor experiences, exhibits and developments as we continue to offer everyone an extraordinary day out.”

ALVA represents the UK’s most iconic museums, castles, zoos and heritage sites.

In the overall table, which was topped by the British Museum, Chester Zoo ranked as the 12th most-visited attraction in the country.

Related: What do TripAdvisor reviewers have to say about Chester's top attractions?

The Upton zoo is also one of five nominees in the category of Large Visitor Attraction of The Year at the VisitEngland Awards 2016, dubbed the Tourism Oscars.

Other acclaim for Chester has seen TripAdvisor name it the seventh best zoo in the world last July.

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