12+ active ZSL promo codes and discounts as of May 2021. Free Zsl.org coupons verified to instantly save you more for what you love. Last Updated: Nov 25, 2019 06:00:36. Situated on the edge of Regent's Park, London Zoo was opened in 1828, under the reign of George IV. Originally intended for scientific research, the zoo was also opened to the public in 1847, giving Victorians a fascinating glimpse into the exotic worlds of far-flung continents. Along with being the world's first scientific zoo, London Zoo also opened the world's first reptile house in 1849, first public aquarium in 1853, first insect house in 1881, and first children's zoo in 1938. London Zoo regularly takes on fundraising initiatives and is an active participant in helping to save endangered species and champion environmental and conservationist causes; this includes a campaign to raise funds to help save the Sumatran tiger.