Yap.Town

のには驚いた

was surprised that

→ の
phrase Rare #25,614
was surprised that Follows a clause or phrase and expresses surprise about it; の turns the preceding statement into something to be surprised about.
JA: 彼が一人で山に登ったのには驚いた。
EN: I was surprised that he climbed the mountain alone.

警官がすぐに到着したのには驚いた。

I was surprised that the police arrived so quickly.

彼が失敗したのには驚いた。

I was surprised that he failed.

私であることが彼女にすぐに分かったのには驚いた。

I was surprised that she immediately knew it was me.

彼が小説を書くのには驚いた。

I was surprised that he writes novels.

彼が不合格だったのには驚いた。

I was surprised that he failed.

とにかく彼が成功したのには驚いた。

I was surprised that he succeeded, anyway.

その薬で私の痛みがすぐにとれたのには驚いた。

I was surprised that the medicine relieved my pain so quickly.