楼門

1. Origins, structure, and basic meaning

• Structure: 楼門 combines 楼, tower or upper story, with 門, gate, and is read ろうもん.
• Basic usage: It denotes a gate with an upper story, as in 寺の楼門 and 楼門の二階.

2. Common pitfalls and similar expressions

• Architectural form
  • The examples' 下から見上げる and 二階 show that this is not merely an entrance but a gate with an upper level.
• Difference from 門
  • 門 is the broad word for a gate, while 楼門 specifically identifies a two-story or tower gate.