Flickr: Old Zoo
- The old zoo, located in Griffith Park, Los Angeles.
- http://www.flickr.com/photos/dsnet/sets/219727/

San Francisco Artillery Fortifications
- Disused fortifications and tunnels near San Francisco.
- http://www.virtuar.com/ysf2/battery.htm

Haloed Moment
- Architecture and urban exploration photography, based in Orange County, California.
- http://haloedmoment.com/

Sutrobaths.com
- Modern ruins of a bath facility off the coastline in San Francisco, CA.
- http://www.sutrobaths.com/

LA Tunnel
- A group dedicated to photos and stories about the L.A. River and its many drainage pipe tunnels. Urban exploration, folklore, accounts, and pictures.
- http://groups.myspace.com/latunnel

Institute for Urban Exploration
- A bi-coastal group, currently operating in San Francisco.
- http://www.unaesthetic.net/iue/

Tribe: SF Urban Adventures
- Adventurers who like to explore nooks and crannies of our lovely city.
- http://tribes.tribe.net/sfurbanadventure

Urban Exploration in and Around San Francisco
- Exploration gallery.
- http://www.multipledigression.com/gallery/exploration

Friends Of Vast Industrial Concrete Kafkaesque Structures
- Photo journal, industrial photographs of the Los Angeles River flood control channel.
- http://seriss.com/people/erco/fovicks/

Public Health Service Hospital
- Photos of the abandoned Public Health Service Hospital (PHSH) in the Presidio of San Francisco, California. This hospital will soon be destroyed/ rehabilitated into housing.
- http://www.loupiote.com/phsh/

Industrial Archaelogy in California
- Abandoned buildings in Richmond, Berkeley, Oakland and San Jose.
- http://www.lakata.org/arch/

Bevatron
- A photo-essay about the Bevatron, a venerable and recently decommissioned accelerator at the Lawrence Berkeley National Laboratory. California.
- http://www.acme.com/jef/photos/bevatron.html