Kansas City, Mo. ? The Kansas City Zoo has turned 100.

It celebrated the occasion Sunday with free admission, cupcakes and the unveiling of a commemorative plaque.

Initially the zoo had little more than a couple of buffalo, a fox, a wolf, a wildcat, a few monkeys and some birds, according to reports. Now the zoo has more than 1,000 animals.

And more animals are coming soon. Work is under way on a polar bear exhibit that is set to open in the spring and expected to help boost the 2010 attendance to 600,000. Penguins are set to arrive in 2012.