Sims 3 Question ...please help?

How do you find the gnomes they say can age up in Generations.I have never found a gnome and would like to have one and watch it age up.But I don't know where or how to get one.I am playing in Bridgeport can I find one in Bridgeport? I heard you can find them around fishing spots,But I have not found one.Is there someplace special I should go or do I need to go someplace in World Adventures? I hope not I hate that.But please can you tell how where or what to do? Thanks for all your kind help!!