Serbia is home to 7 million people and is a land-locked country in the Balkans.
Belgrade is the capital of Serbia and home to around 2 million people. It's separated into old town and New Belgrade (Novi Beograd). It's also one of my favorite places in Europe, because of its raw and unpolished authenticity, combined with the world-renowned hospitality of the serbs.
Pros & cons
Very cheap accommodation and living costs (compared to Central, West and Northern Europe)
Serbs have a very warm hospitality and are very welcoming
A lot of both recent and ancient history to explore
Belgrade is not a typical "European summer vacation destination". It's not a place to come for sunbathing and swimming
Remember that you must register with local police shortly after your arrival. If you stay at a hotel they will likely do it for you, but make sure to get a receipt. If you stay with a local, you must register with the person at the local police station. While it's rare, if you're asked for documentation and doesn't have it, punishment is a fine, and possibily deportation and a night in jail.
Be careful when you mention the recent Balkan wars. Some are okay talking about it, but remember that almost everyone you'll talk to were alive during the war.
Be careful about how you mention Kosovo and Albania. Serbia does not recognize Kosovo as an independent country, and opinion among the people is divided.
Check up on your vaccines for this destination. You might need Hepatitis, TBE and possibly rabies.