Višnjan is a village and municipality in Istria, Croatia. Višnjan is the site of Višnjan Observatory. The observatory is home of several long-running international summer programs for youth in astronomy, archeology, marine biology and other disciplines.

Istria is the largest peninsula within the Adriatic Sea. The peninsula is located at the head of the Adriatic between the Gulf of Trieste and the Kvarner Gulf. It is shared by three countries: Croatia, Slovenia, and Italy, with 87% of surface area being part of Croatia. Croatia encapsulates most of the Istrian peninsula within Istria County.