noun
admission ticket; viewing ticket
A ticket for this word to an exhibition, show, or viewing event. Often used for museums, galleries, and special displays.
美術館の観覧券を2枚買った。
I bought two admission tickets for the art museum.
チケット is a broader, more casual loanword for any kind of ticket, including transportation and events.
Compound of 観覧 (viewing, inspection) + 券 (ticket, certificate).