The Institutes are on Highway 35 which connects Collesalvetti to Fauglia, in the province of Pisa. This road has two names unfortunately (via delle Colline di Lari and via Botra). This is the cause of an inaccuracy of Google Maps which we are trying to solve.
For now, the best way to get information is to request it by clicking on the interactive Google map shown in the column on the right, but taking into account that the point is shown on the right road, but about 800 meters away from the actual position of the Institutes. The correct position is shown in the map reproduced below that you can print to help in the final approach.
In general, the most convenient way to get to Fauglia (from any direction) is on the Genova – Rosignano Motorway exiting at Collesalvetti. After the toll, take the FI-PI-LI road towards Florence, taking the first exit (Vicarello) where, on the SS206 road, you should first follow the signs for Collesalvetti, and then, crossing the town, the signs for Fauglia. You will be on Local SS 35. After a sharp bend downwards you will take a long straight road along which, on the right hand side well before you get to Fauglia, you will see the sign indicating the entrance of the Institutes .