Hi Elena, welcome to Solothurn
! The fall festival (Herbstfest Solothurn or HESO for short) starts soon. It's always at the end of September and runs for two weeks I believe. There'll be lots of booths from local businesses, bars, and bakeries, and a petting zoo with baby pigs, goats, and cows for the kids. Entry is free to all. It's the large tented area currently under construction by the police station at the Baseltor entrance to the historic part of the city, if you've seen it while driving around town.