Buried fiber, hard to attack. Fiber repeater shelters, easy to attack. Their locations are public information, and any non public are trivial to find, in my experience as a cybersecurity professional who seeks out infra vulnerabilities for reporting for fun. Public records, satellite imagery, all OSINT one can do from a workstation.

You could potentially bury them in the ground, assuming you don’t use a generator for backup power. To my knowledge, this is not done today except in urban areas where an underground vault is used for power and comms.

https://www.decommsystems.com/resources/what-goes-into-an-il...