The Municipality of Castel San Pietro Terme is twinned since 1983 with the Croatian town of Opatija, (which Matulji was a fraction of) located on the Istrian coast a few kilometers from Rijeka.

Over the years there have been many collaborative initiatives that have been organized by two cities: the cultural traditions in the culinary trade from folk to those sports, the stays of groups of old castle on the coast of Opatija the exchange of knowledge in character administrative link between the two municipalities.

In the years in which the war has bloodied the former Yugoslavia, Opatija and its surroundings, while not directly involved in acts of war, they have hosted up to ten thousand refugees in their hotels.

Priority need at that time was to provide these refugees' basic needs, including food and clothing.

Even at this juncture dramatic Castel San Pietro Terme was able to maintain alive his partnership with various solidarity initiatives, involving companies, associations, individuals and children in Castel San Pietro Terme in a strong burst of generosity.

After the war, the territory of Opatija was split into four different municipalities: the same Opatija, Lovran Matulji, Moscenicka Braga.

Resumed the contacts twin, both with Opatija that the other towns with which it was signed a new twinning agreement.

With regard to relations with Matulji, the Municipality of Castel San Pietro Terme has never stopped collaborative initiatives and sharing their experiences, especially in the field of public administration and exchange of experience at the famous carnival of Matulji and September Castellano.

Type: International Twinning.
Periods of development: All year round.
Course: exchanges of various kinds (cultural,food and wine, traditional, solidarity).
Project: Municipal Administration.
Organization: Often for the realization of collaborative efforts we make use of the local Pro Loco.