The 125th Annual Christmas Bird Count begins this week. Here's a list of national parks hosting events.

We travel to units of the National Park System to see beautiful landscape, learn about history, view amazing wildlife, and to simply learn new things. We take that knowledge (and photos) back with us to impress family, friends, and coworkers. Just how much of that park knowledge stays with you? Maybe more than you realize.

Low-light interior photography takes a little effort at the best of times, and this is with a tripod. Cave shots captured during one of the tours offered at a cave-centric park unit are trickier, because tripods, bipods, and monopods are prohibited. How do you achieve great cave shots without using a tripod during a tour of a cave unit in the National Park System?

There are several park units within the National Park System that either feature caves, or at least have an explorable cavern or two within their federal confines, including Wind Cave National Park and Jewel Cave National Monument, both in South Dakota. These two parks offer great photo ops both above and below the ground, but cave shots can be a little tricky.