I have, periodically, considered security cameras but have not pulled the trigger yet.

Growing consensus: Looking at POE (power over ethernet) cameras, possibly 4K. Motion activated, stored on NVR, not DVR (higher quality). NVR to be stored in secure cabinet. You can push notifications to a cell phone, if you have a phone line at the site. Night (IR) cameras are limited to 100 - 130 feet, so plan location accordingly.

Other than than, I am still in exploratory phase.