Petrozavodsk — the capital city, the biggest city of Karelia, with a fine collection of neoclassical architecture and a summer hydrofoil service to Kizhi
Kem — a small town on the coast not far from Solovki with a spectacular 18th century wooden cathedral
Kostomukhsa — a large town that functions as a dacha-style resort mostly for Finns every summer and hosts a yearly summer chamber music festival
Olenets — a small historic town near the Alexander-Svirsky Monastery; the only town of size in Karelia where ethnic Karelians constitute a majority
Povenez - small town, here begins Belomorsko-Baltiyskiy Kanal (White Sea-Baltic Channel)
Sortavala — the marble canyon of nearby Ruskeala Park is beautiful, the city of Sortavala has interesting architecture, having been the Finnish showcase of functionalism and Carelianism.
Lake Ladoga — the largest lake of Europe
Valaam Archipelago — famous for its monastery
Lake Onega — second-largest lake in Europe
Kizhi island — famous for beautiful wooden church and other buildings, the whole architectural ensemble of Kizhi island is a UNESCO Wold Heritage Site
Besov Nos Cape — famous for ancient drawings, hammered in the rocks surrounded by outstanding nature. Miles of deserted sandy beaches in both directions, great for wild camping.
Martial waters spa
Vodlozersky National Park
Karelia is known as "the country of lakes." One quarter of Karelia's surface is covered by water including about sixty thousand lakes. The second-largest lake of Europe, Lake Onega, is located in Karelia. The largest lake of Europe, Lake Ladoga is partly located in Karelia (together with Leningrad Oblast). Wherever there is land, there are dense forests covering the ground.
Karelia has strong cultural connection with Finland and the Karelians, for whom the republic is named, are a Finno-Ugric group very closely related to the Finns. The western part of Karelia is a relatively recent Russian/Soviet conquest from Finland, and a bit of a sore spot for the Finns.
Everybody understands and speaks Russian, although many are bilingual in Karelian, Finnish, and, on smaller scale, Veps. A traveler could get by with only knowledge of Finnish, as many native ethnic Russians understand a good deal of the language.
Basic English is widely understood by young people. Swedish is relatively popular foreign language too.
There is a daily overnight train from Saint Petersburg, which leaves around 22:00 and arrives in Petrozavodsk around 07:00.
There is also a daily train to Moscow, which leaves at 19:00 and arrives at 09:00
Recently Russian railroads launched a new train between Saint-Petersburg and Petrozavodsk which departs at 18:00 both from SPB and Petrozavodsk and arrives at 22:50.
The train has cheap and convenient sedentary cars and the price is around 500 RUB. Considering that the traveling time is just 4.50 hrs and that all other trains take 8 hrs and are almost twice expensive it seems to be the best option.
An abandoned Finnish dam at a waterfall near Ruskeala, Karelia
Valamo Monastery - the monastery of the Finnish Orthodox Church. Originally Valamo was placed on an island of lake Ladoga in Karelia but was evacuated whilst in war with the Russians in the 1940s. The monks came with their icons and rebuilt Valamo close to Heinävesi a bit west of Joensuu. The monastery is visited by many Finns, orthodox or not, and is featured in most tourist guides as well. Almost all buildings though are post war and one can't suppress the impression that there is a commercial streak somewhere. However most people come to see the ancient icons from the old Valamo monastery. Boats full of tourists leave during the summer months from Sortavala, Lakhdenpokhya, and Pitkyaranta, as well as big river cruise boats from Saint Petersburg and Moscow. It's also possible to travel here by helicopter from Petrozavodsk.
The Solovetsky Islands and Monastery on the White Sea are another nearby UNESCO World Heritage Site in Arkhangelsk Oblast and can be reached by boat from Karelia.