The answer is: Ai

Joshua 7:3 - If Joshua had prayed to God he would have known not to send the men into battle

The fall of Ai marks a pivotal moment in Joshua's leadership and highlights the critical role of communication with God in decision-making. After a stunning victory at Jericho, Joshua approached Ai with confidence, but his failure to seek divine guidance led to a humbling defeat. It wasn’t just an embarrassing setback; it underscored a deep truth—that even the mighty can falter when they rely solely on their own understanding and strength.

Trivia alert: Did you know that the name "Ai" translates to “ruin” or “heap”? Fittingly, that's what the battlefield turned into for the Israelites originally! God’s guidance can sometimes seem subtle, but in this case, its absence was anything but; the defeat stemmed from Achan's sin, hiding stolen treasures that had been dedicated to God, which created a collective impurity among the Israelites.

Reflecting on this story, we see the constant theme throughout the Bible of humility and inquiry. Think about how it echoes throughout other key Biblical figures who sought guidance before taking critical steps—like Solomon, who famously asked for wisdom instead of riches. This story reminds leaders and individuals today that spiritual unity and humility are essential to overcoming the giants in our life, no matter how small or unassuming the challenge may appear!