Located near Pisa is the amusement park Piccolo Mondo created by the Fornaciai family who have a history of providing amusement rides for children. It boasts of having the highest slide in Tuscany!
The park is open during the summer months:
May - June - July - August - September: daily
October - April: closed Monday
November - March: closed Monday and Tuesday. 
There is free parking and free entrance – but you pay for each ride/activity you do.
Location: Near to Pisa
Website: www.piccolomondo.it/eng/index.asp