By Car:

Take the A11 highway (Firenze-Pisa) and exit at Lucca Est. Then follow the signs to 'Terme di San Giuliano' (white writing on brown signs). After 10 km you enter the town of San Giuliano Terme, here follow the signs to 'Terme'. The light yellow building at the end of the road is the  "Bagni di Pisa Natural Spa Resort". Follow the signs to the 'Hotel Entrance' (beside the main square of the building). 

By Plane:

The G. Galilei Airport in PISA is 10 km away.

By Train:

San Giuliano Terme has a railway station stop on the Pisa-Florence line via Lucca; while the Pisa station which is 10 km away is on the Tirrenica railway line (Sicily-Naples-Rome-Pisa-Genoa-Turin-Milan): one of the main Italian railway lines.