When we were at Johnson Space Center, Houston, this past summer, there were QR codes all over the place. You could use your QRCode Reader app and listen to more information. Or, you could rent a device similar to an iPod, press numbers shown on the information panel, and listen to extra information. We used something similar to this device, at Ellis Island in NY, two years before that.
We have found that most of the more popular national parks have audio tours for purchase available on CD. It's rare that they have them on cassette tape any more.
More info: For those vehicles that still have cassette players (like our pickup), you can purchase a device (probably more likely online or at the bigger electronic stores than at discount dept stores)adapter that will allow you to play other things. It's old technology, but there is a cassette with a wire and a headphone jack that can be hooked into a CD Walkman player, iPod/mp3 player, iPhone/smartphone or iPad/tablet. When our old adapter broke, I bought one at Big Lots for a couple of dollars.
Donna