Bui is a Russian city (since 1536) in the Kostroma Region. It is located at the 103 km distance away from Kostroma. The city has the population of 24 315 people (as of 2015).

The city stands on the left bank of River Kostroma at the mouth of River Vyoksa, 103 km to the northeast of Kostroma. It is a railway junction of the Northern Railroad.

Sights:

The city harbours 3 monuments from the list of cultural heritage sites of federal value: an earthen rampart (1536), a site of an ancient settlement (the 15th - 17th centuries), a shaft and a ditch (1536); and 31 sights from the list of monuments of regional value (generally churches, public and dwelling constructions, including the ensemble of the Bui Railway Station and the main locomotive depot (the beginning of the 20th century).

Not far from the city there are archeology monuments. It is the site Vyoksa-8 of the 6th - 5th millennium BC located 4 km to the southwest of Bui. Another one is the site Vyoksa-10, the 3rd - 2nd millennium BC, on the right bank of River Vyoksa. Near the city there is Zheleznoborovsky Predtechensky Monastery of the 18th - 19th centuries, which is a monument of history and architecture.