越える

1. Origins, structure, and basic meaning

• Structure: 越える (こえる) is a transitive verb for crossing a boundary or obstacle. The examples cross a pass and the sea.
• Basic usage: Travelers go over a steep pass toward a village; a bird makes a journey across the sea.

2. Common pitfalls and similar expressions

• Crossing a mountain barrier and crossing open water
  • Both targets use route or boundary を. 峠 is a land obstacle; 海 a broad space.