Kaliningrad Oblast (Russian: Калинингра́дская о́бласть is one of the numerous Russian oblasts (admininstrative subdivisions). Kaliningrad Oblast is geographically interesting in that is situated between Poland and Lithuania on the Baltic Sea, physically separated from the rest of Russia. Historically, the region is German and the capital was known as Königsberg and it consists of the northern half of historic East Prussia. It was briefly known as Kyonigsberg (Кёнигсберг), (a transliteration of its original German name to Russian) prior to being renamed Kaliningrad (Russian: Калининград), a few years after WWII. The Kaliningrad Oblast thus has only been part of Russia since 1945. Many towns in Kaliningrad Oblast are on the Baltic Sea coast, and have beautiful sandy beaches. It is also the heart of old Prussian kingdom of Brandenburg-Prussia with many ruins of old castles and forts dotting the landscape.
The Kaliningrad Oblast is the northern part of historic East Prussia (German: Ostpreussen), as the southern part is roughly the Warmia-Masuria region of Poland. Since 1945, it has been part of Russia. In 1525 the Duchy of Prussia was founded by the last High Master of the Teutonic Knights Albrecht of Brandenburg-Ansbach who became the first duke of Prussia. From 1618 in personal union with Brandenburg, the duchy was elevated to a kingdom in 1701.
Though the united Kingdom of Prussia (with the capital Berlin) was a member state of the Holy Roman Empire and later the German Confederation, Prussia proper was not a part of Germany (or any other state) but an independent country until in 1871 when the German national state was established under Prussian leadership. Prussia was thereby incorporated into Germany, as its dominant and most powerful state.
After Germany's defeat in WWII, East Prussia's native German-speaking population was forcibly expelled and the area was divided among three countries. The northern part with the capital Königsberg became the area of Kaliningrad Oblast, while the southern part was incorporated into Poland. A third fraction, the district north of the river Memel (Memelland) with the main city Klaipeda (Memel), had previously been split from Prussia and incorporated into Lithuania after WWI, and this was done again after WWII. In the aftermath of WWII, all three areas were ethnically cleansed of the their native German speaking populations.
Because the German speaking inhabitants were forced out and all their property was confiscated, the population of Kaliningrad Oblast consists now mostly of Russian speaking people, but there are still a lot of traces of old German culture (for example, every city in the oblast has an authentic name in German) which, along with the presence of modern Russian culture, makes it an interesting destination for travelers.
Kaliningrad Oblast produces 90% of the world's amber supply.
The Russian language is spoken by more than 95% of Kaliningrad Oblast population. English is understood by many people. While German culture plays a long historical role in the region it is spoken by few.
There are several border crossing points. From the Polish direction: Mamonovo, Bagrationovsk and Gusev. From the Lithuanian direction: Sovyetsk and Morskoye (on the Curonian Spit). You will need Russian visa. Even if you have one it may take days to get in by car. It is probably quicker to fly to Moscow and then fly or get a train to Kaliningrad.
Kaliningrad Oblast has a small international airport, so you may need to fly into Lithuania (Vilnius), Poland (Gdansk or Szczytno) or Finland and take a bus or ferry to Kaliningrad. -Local KD-Avia is flying to several European cities, this is the easiest way to get into Kaliningrad. You can take a LOT (Polish Airlines) flight through Warsaw, every day except Saturday. Aeroflot also has several daily flights from Moscow.