The Slate piece is just a few paragraphs and a couple of pictures of the abandoned guns, along with a map of how to hike to the site in Barbados. Interesting, but what caught my eye was the posted-by byline, which listed not a typical author's name, but instead "Atlas Obscura." In addition, the end of the article included several links to other stories on Atlas Obscura. Well, a name like that is just too intriguing not to check out, right? So I clicked.
As George Takei might say, "Oh, my!" Atlas Obscura turns out to be the self-proclaimed "definitive guide to the world's wondrous and curious places": a kind of encyclopedia of the weird, wonderful, and obscure spots on the globe. In addition to browsing the accumulated stories, you can search by category or proximity to a location (there were a surprising number of covered spots near me) or just click the "Random Place" link if you're feeling lucky. If you create an account, you can mark places that you've been to, or that you'd like to go to; you can give tips on places to be added; and you can edit existing entries.
In addition, the Obscura Society consists (apparently... I've just discovered this place this morning and am still sussing it out) of local volunteers who lead related field trips and other events. Indeed, if Atlas Obscura weren't going to be enough of an Internet Timesink™ on its own, a link on the Events page to an Obscura Society San Francisco salon led me to the website of the Five Ton Crane arts collective, the builders of (among many other cool things) the Burning Man project Raygun Gothic Rocketship (to bring us back around to things that appeal to space-cadets like me), and I think Five Ton Crane's site is going to turn out to be a nontrivial timesink, too!