My children love to play with the Take Along Zoo & Aquarium. I bought it for my youngest when he was 18 months and he had a great time playing with animals and the people. When opened, the two pieces do not lock together but we haven't had any issues with them coming apart during play. The tree is a bit difficult to set up for the younger ones (including my 5 year old daughter). The water streaming from the tree doesn't quite go into the pool as advertised... it spreads all over the place. Nonetheless this is a favourite at our house.