Dorsoduro takes its name from the "hard back" of compacted clay on which it sits, making it one of the most geologically stable parts of Venice. The sestiere stretches along the southern side of the Grand Canal and faces the Giudecca Canal, giving it long, sun-drenched waterfront promenades. The Zattere, a wide fondamenta running the length of the southern edge, is one of the finest walks in the city: gelato in hand, the island of Giudecca across the water, afternoon light reflecting off the lagoon. Dorsoduro is Venice's cultural and university quarter. The Gallerie dell'Accademia houses the definitive collection of Venetian painting from Bellini through Tiepolo. The Peggy Guggenheim Collection, installed in the unfinished Palazzo Venier dei Leoni on the Grand Canal, is one of Europe's most important collections of modern art. Punta della Dogana, the old customs warehouse at the tip of the sestiere, now hosts contemporary art exhibitions in a space redesigned by Tadao Ando. The imposing church of Santa Maria della Salute, built as a votive offering after the plague of 1630, commands the entrance to the Grand Canal. Around Campo Santa Margherita, the main square of Dorsoduro, students from the nearby Ca' Foscari university fill the outdoor terraces of bars and pizzerias well into the night, giving the area a youthful, energetic atmosphere.