If you get the chance would suggest you go to
The Ancient Ships of Pisa
(beside San Rossore railway station)
Via Ranuccio Bianchi Bandinelli (former Via Andrea Pisano)
Visiting hours
Friday, Saturday and Sunday
No reservation needed, with guided tours starting approximately every 90 minutes:
A.M.: 10.00 and 11.30
P.M.: 14.30 and 16.00
http://www.behindthetower.com/en/pisa/sights/a ncientshipsofpisa
I went and it is amazing. During building work all these 2000 year old ships have been discovered and you can visit the site and see all the artefacts, and even one skeleton. Fascinating and better than any other tourist attraction there.