Kaluga — the regional capital is most famous for its role in space exploration as it was the home of Konstantin Tsiolkovsky, a major pioneer of rocket science, and hosts a museum dedicated to his theoretical work; the city's motto is The Cradle of Space Exploration
Borovsk — this town is home to the 15th century Pafnutyev Monastery
Kozelsk — a larger town near the monastery of Optina Pustyn
Maloyaroslavets — a large town, home to Nikolaev-Chernoostrovsky Convent, which includes the prominent Cathedral of St Nikolai, erected in memory of the fierce local battles of the Napoleonic War of 1812
Mosalsk — a small town with a pretty 19th century center, the centerpiece of which is yet another Cathedral of St Nikolai
Obninsk — the region's second largest city is a "hot spot" on the world's radioactive tour circuit as it is home to the world's first nuclear power plant and an accompanying 315m-tall meteorological tower to measure the radiation; the power plant is likely open to the public on guided tours
Tarusa — a small town that was home to one of the 20th century's greatest poets, Marina Tsvetaeva
Optina Pustyn — Probably Kaluga Oblast's most famous tourist destination, this monastic community was a major center of 19th century Russian Orthodoxy, renowned for its startsy (monastic elders who were popularly considered wisemen/healers, many of whom have recently been canonized as saints). The hermitage has impressive literary connections, as it was visited by Nikolai Gogol, Ivan Turgenev, and Lev Tolstoy (among others). One of its elders (Saint Amvrosy), moreover, is widely considered to be the model for Dostoevsky's Father Zosima of The Brothers Karamazov. Following the Russian Revolution, the startsy were driven from the hermitage and the monastery was converted into a gulag and several of its many historic structures were destroyed. Many of the Polish officers massacred at Katyn were first held here at a temporary POW camp within the monastery. The monastery recaptured nationwide attention on Easter 1993 when a satanist entered the monastery and stabbed three monks, including the "abbot," to death, leading the Russian Orthodox Church to declare the monks martyrs. There is much mystic lore surrounding this wild story, amidst claims that the monks demonstrated that they knew of their deaths beforehand.
Tikhonova Pustyn — a 15th century monastery just west of Kaluga, famous for its curative spring water
Sometimes considered a sort of auxiliary destination on the Golden Ring circuit, Kaluga Oblast is probably the most rewarding tourist destination of Western Russia for its many prominent and beautiful monasteries and cathedrals.
Especially outside of the main city, Kaluga, travelers will need to rely on some knowledge of Russian or hire a guide.
Kaluga is an easy 2.5 hour train ride from Moscow, costing only about 10$.