Obscura Day, “an international celebration of wondrous, curious, and esoteric places,” is March 20. Find offbeat treasures in your own hometown, or wherever you plan to be that day.

There’s something for everyone:

Tours for the science nerd

+ In Palo Alto, CA, visit one of the world’s largest working pneumatic tube systems, a 4-mile network through Stanford University Hospital that works to “shuttle specimens and paperwork around at 18 miles per hour”

+ Head to Dunedin, New Zealand to see the Beverly Clock, a 146-year old science experiment, powered solely by atmospheric changes

+ Tour Reed College’s nuclear reactor in Portland, OR (controlled by undergraduates, God help us)

+ Take a tram ride 65 stories below street level through the Kansas Underground Salt Museum built on an actively mined vein of salt that stretches from Kansas to New Mexico. (The world’s oldest organism was found here!)

+ Stroll the poison garden at Northumberland, England’s Alnwick Castle

Modern world oddities

+ Spelunk in Tokyo’s as-yet-unfinished massive storm drain system, G-Cans, built to handle 200 tons of water a second during monsoon season.

+ Climb down a ladder and explore the abandoned Atlantic Avenue subway tunnel in Brooklyn

+ Take a Strangelovian flashlight tour of an abandoned NATO command bunker buried in a hillside in Kristiansand, Norway

+ See a railroad tunnel in Sydney that’s been colonized by bioluminescent glowworms

+ In Butte MT, visit a Superfund site: the acid-filled lake left by an open-pit copper mine

+ Tour abandoned residential developments—modern ghost towns—in West Palm Beach FL (tract housing overrun by Everglades flora and fauna), and California City, CA (pictured below in a Google Map satellite shot, no buildings, just streets to nowhere).

Downright creepy wunderkammers and museums

+ Take a private tour of Philadelphia’s Mutter Museum

+ See the jackalope’s kin at Portland, Maine’s International Cryptozoology Museum

+ Explore the Icelandic Phallological Museum in Husavik. (That’s right, a museum dedicated to male genitalia.)

Outsider art destinations

+ Visit Coral Castle outside Miami

+ See one man’s vision of the Garden of Eden in Lucas, Kansas

+ Participate in a scavenger hunt at the American Visionary Art Museum in Baltimore

+ In Sandia, NM, visit Tinkertown, a kooky 22-room museum (built from wagon wheels, store facades and 50,000 glass bottles) filled with one man’s personal collection of carved miniatures and “ephemera”

There’s much more—artist studios, science museums, tree houses, public art installations, historical walking tours, odd rock formations—and events are being added as they come in. Get on the site and reserve a space because some tours have already booked up, especially those limited to small groups. (If, by the way, one of your favorite nutty local attractions is somehow overlooked by the wide-ranging list, you can create your own Obscura Day event and post it.) Celebrate the offbeat!

Ann Shields is the Senior Online Editor at Travel + Leisure.