“Fantastic views and historic sites around every corner with only bicycle traffic.”
— Bob Gardner
This is the main thoroughfare for touring around the island with many places to explore along the way.
From the ferry pier, take the paved road towards the visitor center then head up the bypass trail on the left that winds its way to the main Perimeter Road. The road isn't flat, as it encircles the island there are some ups and downs with one notable steep section on the southeast side near an old Nike-missile site where a "Walk Bicycles" sign is posted in the downhill direction (counter-clockwise).
There are beautiful views all around with the best along the west and south sides, facing the Golden Gate Bridge, Alcatraz and San Francisco. All of the important historical sites are encountered on this road. Near the Immigration Station is the start of the Fire Road Loop
, the lesser-used dirt road that cruises around the island a few hundred feet higher. Several side trails pass through some of the facilities or lead to shore and beach areas.