Friendly Biysk, 160km southeast of Barnaul, is not worth a special detour but its old town merits a wander if you are passing through en route to or from the Altai Mountains, for which it’s the nearest railhead.
One of only three cities created on the orders of Peter the Great (the others were Moscow and St Petersburg!), Biysk was founded in 1709 at the junction of the Biya and Katun Rivers, but was quickly burnt down by the Dzhungarian Mongols. Biysk was reestablished 20km to the east in 1718. Unfortunately, nothing remains from this period. Most of the well-preserved architecture of the historic centre dates from the late 1800s.