Samokov is famous (locally, hardly anyone in the outside world heard anything about this little city) mainly for two things: Bulgaria's best potatoes, and the bus station that lets you change from the bus from the capital to a small shuttle to Borovetz ski resort. These two things are very important, of course, but there's more.
Samokov is a great place on it's own. Picturesque, with ever-present backdrop of the mountains and the Iskar river cutting the city roughly in half. Perfectly walkable (and bikeable), with plenty of parks in and just outside of the city. Drowning in green in Summer. Speaking of which, being the highest city in the country (almost 1000 meters above sea level), makes Samokov the best getaway during the heatwaves. But don't forget your sun screen and a jacket for the night.