Mystery Structure on the Bay
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I have no clue what this is. I always drove past it on U.S. 101, and could never figure it out. I thought maybe it’s some sort of vent for something underground like sewers or something. There isn’t anything else around here: its not along a walk to or from anywhere, though there is a sidewalk going North.
Then I finally stopped. This isn’t just some incidental structure. There is a metal gate with dolphins on it and a plaza with a large spiral pattern on it. If you zoom in on Google Maps you can see it. Clearly if this were only built to be seen by maintenance workers, they wouldn’t have included such details. There are signs saying parking on the road is not permitted, so I clearly am not the only one to stop.
On the pillar structure, there are two signs. On the door is a small one:
OPENING THIS DOOR
ACTIVATES THE ALARM
Note it says “the” alarm and not just ‘an’ alarm. Painted below the door stenciled in red on a white background is:
CONFINED SPACE
PERMIT REQUIRED
Where do I get a permit, I wonder? A search on the internet turns up a little from OSHA. On the wall across the plaza in a few locations another similar warning stenciled in black on yellow:
CONFINED
SPACE
I suppose there is some inside to this structure, but wouldn’t one know that a confined space is such when one tries to get in? The outside certainly isn’t confining: It’s pretty open with a good panorama of the Bay and the highway. I never see signs on a closet or by the entrances to normal maintenance shafts that have such warnings.
Leaving the plaza and walking North on the sidewalk you see some other strange things. The sidewalk is over what appears to be a storm drain, with dam-like controls to allow overflow into the Bay. There is a machine or metal box on the walk with a plastic tube going to the drain-thing. It has a strip of black an yellow caution tape on it and the following text stenciled in black on it:
303
BERM-FMS
274-0285
Nearby on the other side of the walk, on the grass between that and the road is a machine in a locked cage with a metal tag with blue writing on white:
COSYSCO
Walnut Creek, Co. 94596
| CONTROL VOLTS | 120 VAC | CYCLES | 60 |
| POWER VOLTS | 500 WATTS | SER.NO. | E81115 |
| MODEL NUMBER | S360 | E815 |
The serial number and model number were hand written, and the former is hard to make out. Cosysco apparently makes pollution controls and only has a P.O. box. These two machines may have nothing to do with the plaza and the pillar, but I include them anyways because they may help.
Also nearby, on the walk on the ground is a survey marker in the center of a white X:
CALIF. DEPT. OF TRANSPORTATION
CA-HPGN-DENSIFICATION
STA 04 GF
1994
I found this information on the benchmark. The benchmark may be unrelated to the other structures.
So what is this place?
| Nearest Airport | SFO, OAK |
| Street Address | Harney Road |
| Cross-Street | Alanna Road |
| Secondary Cross-Street | U.S. Highway 101 / Bayshore Freeway |
| Neighborhood | Candlestick / Bayshore ? |
| City | Brisbane |
| County, Parish, or Township | San Mateo |
| State, Province, or Region | California |
| Country | USA |
| ZIP or Postal Code | 94005 |
| Latitude | 37.70594 degrees |
| Longitude | -122.39344 degrees |
| Public Transit Information | MUNI bus 56 |
| Parking | There is a driveway with room for 1-2 cars. |
| Contact E-mail Address | |
| Contact Telephone | |
| Contact Fax | |
| Official Website | |
| Related Website | http://www.geocaching.com/mark/details.aspx?PID=AB7679 |
| Admission Price | free |
| Hours | 24/7 |
| Vegan Dining Options | Might make a good picnic spot. Though the marshy smell may put you off. |
| Wheelchair Access | Yes, but you may have to take the long way around the gate. |
| Potential Hazards | Confined spaces. |
| Special Events at Attraction | Wish I knew |
| Best Thing to See or Do Here | It's a puzzle of a mystery |
| Last Visited | November 2005 |


