*Transportation to IPhT Saclay from Paris:
Train RER B to Le Guichet, Walk to bus station (follow the crowd), Bus 9 to Ormes des Merisiers, Walk to IPhT building 774
More information here
*Directions to ENS Physics Departement:
Nearest RER B station is Luxembourg
Enter building at 24 rue Lhomond (Ring the bell if the gate is closed)
Gmap from Luxembourg garden can be found here