The Big Dilemma For City Cats - keep them indoors only OR let them be an Inside/Outside cat

Living in a big city most likely means living in a condo, not a house with a big yard. For many cat owners it's a huge dilemma whether to let their cat roam through the city streets exposed to all kinds of danger or keep them indoors ONLY. We decided long ago, to let our kitty Mona Liza go outside and she seems to be the happiest cat in the neighborhood. She goes out few times a day. We're really fortunate to have few trees around our building and spacious yard with flowers.
So, the question is to let kitty out or to keep kitty in?


Kitty Mona Liza in her natural environment - on the tree chasing a squirrel