From 287S get off at Route 24 East.
Exit 2A towards Morristown.
After the 4th light (the Morris Museum will be on your right), get into the left lane.
There will be a mailbox on the left side of the road, the entrance is directly after that on your left.

From Parkway
Take Parkway to Route 78. Get off at Route 78 West. Stay to the right and take Route 24 West.
Exit 2A towards Morristown.
After the 4th light (the Morris Museum will be on your right), get into the left lane.
There will be a mailbox on the left side of the road, the entrance is directly after that on your left.