Network security cameras
easy to setup, minimal cabling, decent features, and more favourably priced than cctv cameras, network based security cameras are an emerging market
they don't cost much, in fact some webcams can be used by network video recorders in lieu of the proper hardware.
they're easy to connect, depending on which cameras you have they can connect via power over ethernet, wifi plus power pack, or LAN plus power pack. this means in difficult to access areas all you really need is a PoE injector and a lan cable someplace accessible and simply run a long lead to the camera.
the recorder is simple to use, usually just a program running on a "server", the better ones recognise the cameras with some hints on where to look on the network. Then, with some login details later you have motion detection recording video's of bugs and the occasional passing car.
We've caught a kangaroo beating up an unsuspecting dog, we discovered a stray cat wandering the property. we've caught several cars using the driveway for doing u turns. while not everything captured is super interesting. it's what gets captured when it's needed that's important.