Place Photos
Do you take place photos? I started doing this when I switched to a digital camera. With film, you only had a few (relatively speaking) pictures before you needed to swap out film canisters and then you could label the cartridge. With digital cards, you can take hundreds, and now thousands of photos without ever removing the SD card.
After forgetting where I had been a few times, I started taking a photo of whatever signage I could find before I took any other pictures in the area. For most parks, this was easy. They have multiple options with their name listed. For small areas there might be a street sign, or even use the map on the phone to show where you are.