、？
Torii, you mean… the red structure at the top of the stairs?
Literal
Torii [quotative-と] say-[when-と], stairs [obj-を] went-up place [at-に] was red object?
A tentative identification. 鳥居 (torii) is the distinctive red gate structure marking the entrance to a Shinto shrine — probably the most visually iconic Japanese religious symbol. と言うと ('when you say X / speaking of X') is a discourse marker for picking up a previously-mentioned topic. 階段を上がったところ ('the place where (one) went up the stairs') uses ところ as a location-nominalizer. オブジェ is the loan 'object' (specifically art-object, installation), written in katakana. Tentative, exploratory speech.