- 戒备森严 jièbèisēnyán heavily guardedTight security is in force; under heavy guard.
- 壁垒森严 bìlěisēnyán closely guardedstrongly fortified or closely guarded by defensive works
- 森严壁垒 sēnyánbìlěi strongly fortifiedclosely guarded or strongly fortified; also used to describe a sharp division or clear boundaries between opposing sides
- 门禁森严 ménjìnsēnyán guarded closelyThe entrance is strictly guarded; refers to a place where access is heavily restricted and security is tight