Final answer:
Plovdiv and Varna are cities in Bulgaria, a country with a varied landscape from the Black Sea coast to the Balkan Mountains. Bulgaria's economy includes agriculture, industry, and an emerging tourism sector, with a history intertwined with the Byzantine Empire.
Step-by-step explanation:
The cities of Plovdiv and Varna are located in Bulgaria, a country situated at the crossroads of Europe and Asia. Bulgaria features a diverse landscape, with the Black Sea coast being a notable region, where Varna serves as a significant coastal city. Plovdiv, another major city, is known for its rich history and cultural heritage. Bulgaria's diverse geography includes expanses like the Balkan Mountains and the fertile plains that enable extensive agricultural activity. The Danube River also marks part of the border with Bulgaria, on its course toward the Black Sea. Bulgaria's economy, which includes mining, industry, and agriculture, is still transitioning to a capitalist system, with tourism also emerging as a vital segment.
Bulgaria became a member of NATO in 2004 and joined the European Union in 2007. The historical and cultural significance of Bulgarian cities, along with the nation's varied landscapes, are of great interest to international tourists. The country's proximity to Byzantine architectural developments and its storied past, including its adoption of Christianity in the 9th century, make it a rich subject of study in both geography and history.