According to forum posts, Belgrade offers stunning attractions including St. Slava Temple, Kalemegdan Fortress, and Skadarlia. The city also provides a vibrant river life and numerous suburbs worth exploring.

Travelers have highlighted Novi Sad for its Petrovaradin Fortress and the nearby Fruška Gora with its monasteries. Additionally, Sremski Karlovci is noted for its charm and can be easily accessed from Novi Sad.

Some travelers said that the Uvac Canyon, Sargan 8 railway, and Mokra Gora in the Zlatibor region are essential visits for nature lovers. The Iron Gates on the Danube, featuring Golubac Fortress, and the Tara National Park also come highly recommended.

For those interested in Serbian cultural heritage, posts suggest visiting the Manasija Monastery, Studenica Monastery, and the historical city of Niš. The ethnic village of Sirogojno and Gostilje Waterfall near Zlatibor also offer unique experiences.

According to forum posts, direct train options from Belgrade to some destinations are currently limited or non-existent. For instance, there are no trains running from Belgrade to Zagreb, and the train service from Belgrade to Sofia has also been discontinued for some time.

Some travelers mentioned that while there is no direct train from Belgrade to Novi Sad, one can travel by train with a change in Belgrade when heading to Niš from Novi Sad. Despite this option, the journey between Belgrade and Niš is slow, taking nearly 6 hours to cover less than 250 km, with the train stopping frequently.

For many users, buses are suggested as a more reliable alternative when direct trains are not available. For example, direct buses are recommended for travel from Belgrade to Sofia, and there are frequent buses between Subotica and Belgrade.

According to forum posts, it is recommended to avoid exchanging currency at airports, banks, and other typical tourist spots due to unfavorable rates. Travelers have suggested that the best places for currency exchange are local exchange offices, particularly those found in city centers like the Bulevar kralja Aleksandra in Belgrade.

Some travelers said using cards for most transactions is convenient, and ATMs are readily available for withdrawing cash. It's advised to have a small amount of dinars for minor expenses. When using ATMs, always choose to be charged in the local currency to avoid extra fees from dynamic currency conversion.

For many users, carrying euros or dollars and exchanging them in Serbia offers a practical solution. It's noted that while euros are widely accepted for exchange, other currencies like pounds and dollars can also be exchanged without significant issues, but the rates may vary slightly.

According to forum posts, having a Kosovo stamp in your passport is not fundamentally an issue for entering Serbia. The critical factor is the route of entry; if you enter Serbia directly from Kosovo without a prior Serbian entry stamp, entry may be denied. However, if you enter Serbia from another country after visiting Kosovo, there should be no issues as long as you follow the correct entry procedures.

Some travelers have reported that Serbian border authorities have occasionally cancelled Kosovo stamps in passports. This appears to be an isolated incident rather than standard policy. Travelers are advised to enter Serbia with a Serbian stamp first before visiting Kosovo to avoid any complications at the border.

Travelers have mentioned that government advice, such as from the UK, emphasizes the importance of having a Serbian entry stamp if coming from Kosovo. It's noted that issues arise primarily when trying to enter Serbia from Kosovo without this Serbian entry stamp.

According to forum posts, SIM cards can be purchased in Serbian cities like Subotica and Novi Sad. In Subotica, however, stores may not be open on Sundays, making Novi Sad a more reliable option for purchasing on that day.

Travelers have mentioned specific locations for buying SIM cards. For instance, in Novi Sad, Yettel has a stall in the central corridor of the Big Shopping Mall, and Operator A1 also has an office on the ground floor of the same mall.

Some users have indicated that SIM cards are available at airport locations, particularly at the baggage claim area, providing convenience right upon arrival in Serbia.