The Sanctuary of the Sacred Heart of Jesus, atop Mount Santa Luzia, is a must-visit in Viana do Castelo, renowned for its stunning architecture and panoramic views of the city, river, and Atlantic coast. It is highly accessible via car/taxi or the historic Elevador de Santa Luzia funicular from the city center, which offers an experience in itself; the main areas are generally wheelchair-friendly. While easily enjoyed solo to appreciate the views and intricate details at your own pace, guided visits can offer deeper historical and architectural insights. The sanctuary is open year-round, though a clear day is recommended for the best views, as winter months can be foggy. Entrance to the sanctuary is typically free, with a small fee for the funicular ride (a few euros) and an optional climb to the dome for even more expansive vistas (around €1-€2). A typical visit, including travel and exploration, lasts between 1.5 to 3 hours. Don't forget to wear comfortable shoes and bring a camera for the breathtaking photo opportunities.