Pisa is a city celebrated for its Leaning Tower, an architectural project begun in the 12th century that unintentionally became world-famous for its unintended tilt. This tilt is due to the soft ground on which it was built, which could not properly support the structure's weight. Beyond the tower, Pisa is also renowned for its rich history in art, education, and research, being home to the University of Pisa, one of Italy's oldest universities. The city offers a blend of vibrant street life, cultural landmarks, and picturesque views along the River Arno.