This is the 522nd most frequent Japanese word.
いけ
Pond.
Here, 'いけません' means 'not allowed' or '禁止,' being part of the prohibition verb structure.
いいえ、そこへ行ってはいけません。
No, you are not allowed to go there.
In this sentence, '行け (いけ)' is the imperative form of the verb '行く,' meaning 'to go,' used to command someone to move or proceed.
彼は「行け、行け！」と叫んだ。
He shouted, "Go, go!"
In this context, 'いけ' means 'pond,' referring to a body of water in the garden.