One of my favorite hobbies I’ve picked up in Japan is 御朱印集め (go-shuin atsume, collecting seal stamps). 御朱印 (Go-shuin) are the red-ink stamps that you can get at 神社 (jinja, shrines) or お寺 (o-tera, temples) that signify you have visited that place of worship.
These stamps have the name of the shrine or temple as well as the date you visited written on them in elegant calligraphy. Collecting 御朱印 has often served as the impetus for me to visit and explore areas of Japan I would normally not get off the train at. And I’m not alone: Collecting 御朱印 has recently become quite popular and led to the coining of the term 御朱印女子 (go-shuin joshi), or “go-shuin girl.”