warning and prohibition sign near the ravine because there is a

abyss acuity advertence advertency attention banner barred billboard bluff care cartel caution chasm cliff danger dangerous dangerousness drop dropped fall fallen falling forbidden gulf hazard hazarding hazardous inhibition interdiction jeopardy notice peril perilous poster precipice prohibition ravine reef risk risky rock rocks sign signage signboard slump substances taboo topple treacherous unsafe