From baby chimps and hippos to anti-aircraft guns during World War II, the Moscow zoo has had a rich history since it was founded on Feb. 13, 1864.

Celebrating its birthday on Wednesday, we look back at archival photographs of how the grounds and residents of the zoo have changed throughout the years.

Having started off as a “zoological garden” with 153 wild animals and birds all those years ago, today it houses more than 8,000 animals belonging to more than 1,000 species.

Here’s a look at the zoo from its earliest days to the present.