Once a mayor Silk Road city, Herat would be flooded with visitors was is not for its Afghan location. The city has a lot to offer and can rival the most famous of Central Asia's Silk Road gems: The 800 year old Jama Masjid (Friday Mosque) stands out in particular, but the city also hosts a huge citadel and mosques, madrassas, mausoleums, and minarets - most of these dating back to the days of the Silk Road golden age. Add to the history a lively market, legendary glassblower Sultan Hamidi's shop and a number of idyllic villages in the surrounding countryside, Herat is a quite the destination for those few visitors it sees every year. Just be prepared to stop for a lot of offers for tea and a friendly conversation with some very curious locals.
Warning: Kidnapping for ransom of locals have been on the rise the last few years. Precaution is advised.
On a positive note, the Herat province is one of the most peaceful in Afghanistan and Herat is accessible from both the borders of Turkmenistan and Iran as well as with flights from Kabul.