Trégastel, situated on the Pink Granite Coast, has been inhabited since prehistoric times, evidenced by the presence of numerous megalithic sites including dolmens and menhirs.

Geographically, Trégastel is characterized by its dramatic coastline of pink granite rocks sculpted by the sea and wind, creating unique formations and sheltered coves.

The population of Trégastel has experienced gradual growth throughout the 20th and 21st centuries, driven primarily by tourism and the appeal of its coastal lifestyle, with a significant seasonal increase during the summer months.

The local economy of Trégastel is heavily reliant on tourism, with hotels, restaurants, and souvenir shops forming a significant portion of its economic activity.

Fishing, although less prominent than in the past, continues to play a role in Trégastel's economy, with a small fishing fleet based in the port of Coz-Pors.

The Celtic heritage of Trégastel is reflected in its language, with Breton influences evident in local place names and some cultural traditions.

The Forum de Trégastel, a unique covered seawater swimming pool and leisure complex, is a major landmark and attraction, drawing visitors year-round.

The Île Renote, a small island accessible by a natural causeway at low tide, showcases the distinctive pink granite landscape and diverse flora and fauna.

The Chapelle Sainte-Anne, a small chapel overlooking the sea, is a historical site of religious significance and a popular spot for reflection.

The Musée des Télécommunications, although located in nearby Pleumeur-Bodou, reflects the region's pioneering role in telecommunications, as the first transatlantic telephone cable landed nearby.

Trégastel, like many Breton communities, observes traditional festivals and celebrations rooted in Celtic and Christian customs, including Pardons (religious festivals).

Although not directly involved in major national political events, Trégastel has consistently participated in the democratic process through local elections and regional governance.

Trégastel's location on the Pink Granite Coast contributes to its environmental importance, attracting researchers studying coastal erosion and biodiversity.

The coastal paths of Trégastel, part of the GR34 (sentier des douaniers), offer breathtaking views and opportunities for hiking, promoting eco-tourism.

Trégastel's commitment to preserving its natural environment has led to initiatives promoting sustainable tourism and protecting its coastline from over-development.