This paleoseismic pit in Fremont, California, was opened at the site of a previous trenching study for use as a public education exhibit in 2006, during the centennial of the 1906 San Francisco earthquake. The docent's hand is pointing to a remnant of the earlier trench. The string directly behind his head marks the active trace of the Hayward fault. The dark sediments on the left were carried here by earthquakes and aseismic creep over thousands of years, and here they contrast strongly with the light sediments on the right side. Charcoal has enabled dating of the dark deposits at about 9000 years old.
A pit, rather than a trench, allows the ground to be viewed at leisure, without needing bracing or requiring visitors to wear hard hats.