Open Infrastructure Map is a view of the world's infrastructure mapped in the OpenStreetMap database. This data isn't exposed on the default OSM map, so I built Open Infrastructure Map to visualise it. If you want to edit the data and you're new to OpenStreetMap, check out learnOSM.
If you already have some OSM experience and want to start tagging infrastructure things, take a look at the tagging guidelines for power and telecoms.

SHODAN has a service where you can use them to monitor your your stuff if you have an account with API access. Schedule and run scans, get alerts if something new or unexpected appears. Has its own API and CLI tool, too.

A wiki full of information pertaining to the construction of sustainable communities, from engineering to water purification, construction, and agriculture.

An archive website about coldwar infrastructure in the US. Has documentation about communications systems and facilities.