Redwood National Park
Collaborative group of parks in California.
Each edition grades its towns against each other only.

This is a list led by parks & monuments, 4 of its 5. O'Brien itself has none of them. Visits to Redwood National Park run to about 1.2M a year. The best-known trip out is to Mount Ashland, 51 mi away.

Collaborative group of parks in California.
The towns around it, and where to stay →
Head to the southwest for most of the 5 on the list.
Orange: O'Brien. Numbers: the best-known places, matching the list below. © OpenStreetMap contributors
These 9 are within 60 miles, none in town.
Collaborative group of parks in California.
National monument in the United States.
Ranked by how many people look them up, so the famous places lead and the local favorites follow.
Parks and trails in O'Brien → · O'Brien’s history →
Redwood National Park: Michael Schweppe, CC BY-SA 2.0 · Oregon Caves National Monument and Preserve: David Monniaux, CC BY-SA 3.0 · Jedediah Smith Redwoods State Park: Mario Vaden (talk · contribs), Public domain · Six Rivers National Forest: Clinton Steeds, CC BY 2.0 · Mount Ashland: Alex Lockhart, Public domain · Brother Jonathan: Unknown authorUnknown author, Public domain · Prairie Creek Redwoods State Park: California Department of Parks and Recreation, Public domain · Lithia Park: Unknown, CC BY-SA 3.0 · ScienceWorks Museum: Roberto J. Galindo, CC BY-SA 3.0