The number 11 has a special significance in Solothurn and can be found throughout the city.

Solothurn is home to 11 museums, fountains, chapels, churches and a clock whose dial only shows 11 hours. Even the local beer brand is known as «Öufi» («eleven» in the local dialect).

The masterpiece inspired by this «magic number» is St. Ursus Cathedral, the landmark of Solothurn. Master builder Gaetano Matteo Pisoni from Ascona was so fascinated by the ubiquitous figure in 1762 that he designed the church entirely in line with it. The bell tower measures 6 x 11 metres and houses 11 bells, while the cathedral's 11 altars are simultaneously visible from just one place in the nave – the eleventh black stone. Its kneelers are arranged in rows of eleven and the monumental outer staircase comprises three sets of 11 steps. The number of pipes in the great organ is divisible by 11. True to the theme, the cathedral took 11 years to build (1762 – 1773).

A themed tour about the number 11 can be booked with Region Solothurn Tourismus.