Plovdiv printing-press. The city's traditions as a literary centre are preserved by the first public library in Bulgaria, the Ivan Vazov National Library, the 19 "chitalishta" (cultural centres), and by numerous booksellers and publishers. The library was founded in 1879 and named after the famous Bulgarian writer and poet Ivan Vazov who worked in Plovdiv for five years creating some of his best works. Today the Ivan Vazov National Library is the second largest national library institution with more than 1.5 million books, owning rare Bulgarian and European publications. The city has traditions in iconography since the Middle Ages. During the
Plovdiv the year. Mists are common in the cooler months, especially along the banks of the Maritsa. On average there are 33 days with mist during the year. The history of Plovdiv spans more than eight millennia. Numerous nations have left their traces on the cultural layers of the city. The earliest signs of habitation on the territory of Plovdiv date as far back as the 6th millennium BCE. Plovdiv has settlement traces including necropolises dating from the Neolithic era, roughly 6000–5000 BCE, like the mounds Yasa Tepe 1 in Philipovo district and Yasa Tepe 2 in Lauta park. Archaeologists have