We all know that a Denver Public Library (DPL) card is a ticket to limitless books and video tapes. But did you also know that your library card can get you free passes to local museums, help you learn a foreign language and detect air leaks in your home?

All for free.

There’s no better deal around. Anyone in Colorado can obtain a DPL card, and its amazing perks are rarely advertised.

Here’s just a few benefits your card can bring you, as noted by Westword.

Free museum entrance: Reserve a pass up to 30 days in advance and you can head into the Denver Museum of Nature & Science, History Colorado, or Museum of Contemporary Art for free. And you bring a friend: Admission is valid for two adults.

Draft Check Meter: Worried about your energy bills? Borrow a meter that uses an infrared sensor to detect cold-air leaks in your home.

Power Check Meter: After you plug air leaks in the house, check out a meter that tells you which appliances are the biggest drains on your electric bill. This way, you can discover what to unplug to save on your electricity usage.

State Park passes: Feel like putting your book down and getting out in the wild? This is a perk you can’t pass up: Check out a weeklong pass to any Colorado state park. It will admit a car full of people—and even comes with an “adventure backpack” that includes binoculars, maps and guides for identifying various plants and animals.

Language-learning software: DPL cardholders have free access to online language courses. Choose French, Japanese, German, Greek, Italian, Russian—and more. Trés magnifique!

Photo by Eliabe Costa on Unsplash