By car: The simplest route is via the A44 (to the west of Leiden), rather than via the A4, which passes Leiden to the east.
Take the exit Leiden/TransFerium (exit number 8) and follow the Leiden direction. Take the N206 (Plesmanlaan) and then follow the signs to the Bio-Science Park. At the second set of traffic lights turn left, in the direction of the Bio-Science Park. Follow the road (Einsteinweg) which bends to the left until you approach a roundabout.
Go straight on at the roundabout and you will see the Gorlaeus Laboratories on your right hand side (the large dish-shaped building). The car park is on your left hand side.
By train: Leiden Central station is about 10 minutes from The Hague, 35 minutes from Amsterdam, 30 minutes from Rotterdam and 45 minutes from Utrecht.
By bus (from Leiden Central station): Take bus 43 to The Hague, as far as the 'Universiteitsterrein' stop.
By bike (10 minutes) or on foot (25 minutes) (from Leiden Central station): Leave the station via the rear exit (the LUMC/Oegstgeest side), towards the main entrance to the LUMC. By the main entrance, keep to the right and carry on until you have passed the parking garage (Albinusdreef). Go left at the roundabout, into the Sandifortdreef. Follow this road until the next roundabout. Keep to the right and you will find yourself on the Zernikedreef. Carry on along this road until you meet the Einsteinweg. Turn right into the Einsteinweg. The Einsteinweg will bring you to the Gorlaeus Lab., the large, dish-shaped building on your right hand side, just past the roundabout.