階段の上

at the top of the stairs

→ 階段
phrase Rare #45,220
at the top of the stairs 上 can also mean “on” or “above,” depending on context.
JA: 階段の上に猫がいます。
EN: There's a cat at the top of the stairs.

彼は階段の上に恐ろしい顔を見た。

He saw a terrifying face at the top of the stairs.

階段の上の?

Upstairs?

— レベッカ (1940)

階段の上

At the top of the stairs

— ライフ・イズ・ビューティフル (1997)

昨年私寮の客間に住んでたの階段の上よ

Last year, I lived in the guest room at the top of the stairs in the dormitory.

— サスペリア (1977)