Complex sentence: Established in 1931 at the request of deceased Cecil Rhodes, it was a very popular attraction in Cape Town until it's closure in 1975 due to a combination of the financial burden that the Apartheid government faced and an increase in animal welfare standards.
Split into simpler sentences: Established in 1931 at the request of deceased Cecil Rhodes, it was a very popular attraction in Cape Town until it's closure in 1975. The zoo shut down due to a combination of the financial burden that the Apartheid government faced and an increase in animal welfare standards.