at a glance; at first sight
Used to describe an initial impression or superficial observation, often implying that the reality may be different.
See also: 一見 (いっけん)
At first glance, this problem looks easy.
At first sight it's an ordinary house, but inside it's very spacious.
Standard kanji spelling for this adverbial phrase.
Variant using 所 instead of ところ; slightly less common but still encountered.
Phrase composed of 一見 (a glance) + した (past form of する) + ところ (place/extent), literally 'at the place where one has taken a glance'.