Fresco

Fresco (plural frescoes) is any of several related painting types. The word fresco comes from the Italian word affresco which derives from the adjective fresco ("fresh"), which has Germanic origins. Fresco paintings are done on wet plaster.

Selected examples of Italian frescoes:

Astelseprio
Italian Late Medieval-Quattrocento
Panels (including Giotto, Lorenzetti, Martini and others) in upper and lower Basilica of San Francesco d'Assisi
Giotto, Cappella degli Scrovegni (Arena Chapel), Padua
Camposanto, Pisa
Masaccio, Brancacci Chapel, Santa Maria del Carmine, Florence
Ambrogio Lorenzetti, Palazzo Pubblico, Siena
Piero della Francesca, Chiesa di San Francesco, Arezzo
Ghirlandaio, Cappella Tornabuoni, Santa Maria Novella, Florence
The Last Supper, Leonardo Da Vinci, Milan (technically a tempera on plaster and stone, not a true fresco)
Sistine Chapel Wall series: Botticelli, Perugino, Rossellini, Signorelli, and Ghirlandaio Luca Signorelli, Chapel of San Brizio, Duomo, Orvieto
Luciano Medevici, a monochromatic fresco, destroyed in a fire in 1944.

The Leaning Tower of Pisa

The Leaning Tower of Pisa (Italian: Torre pendente di Pisa) or simply The Tower of Pisa (La Torre di Pisa) is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa. It is situated behind the Cathedral and it is the third structure in Pisa's Piazza del Duomo (Cathedral Square).

Although intended to stand vertically, the tower began leaning to the southeast soon after the onset of construction in 1173 due to a poorly laid foundation and loose substrate that has allowed the foundation to shift direction.

The height of the tower is 55.86 m (183.27 ft) from the ground on the lowest side and 56.70 m (186.02 ft) on the highest side. The width of the walls at the base is 4.09 m (13.42 ft) and at the top 2.48 m (8.14 ft). Its weight is estimated at 14,500 tonnes. The tower has 294 steps. The tower leans at an angle of 5.5 degrees. This means that the top of the tower is 4.5 meters from where it would stand if the tower was perfectly vertical.

This dome is an architectural marvel

No one knows how the Romans made a non-reinforced concrete dome that survived two millennia. Apparently, a dome of this size made from modern concrete would collapse under its own weight.