In May and June the Kazanlak valley is filled with wonderful aroma – at that time of the year the oil-yielding rose is in blossom from which the rose oil is produced that has made Bulgaria famous worldwide. In its honour in the beginning of June at the annually held Rose Festival a Queen of the Rose is crowned and traditional rituals are performed with authentic atmosphere. The programme is full of high spirits, songs and dances and is worth experiencing. One can see the tombs of the Thracian kings in the town of Kazanlak that date back to the 4th-3rd century B.C. that are included in the list of UNESCO World Heritage Sites. Marvellous wall-paintings and various items such as the golden mask of the mighty Teres I and the bronze head of the Thracian king Seuthes III were found in them, it is also worth visiting the archaeological museum and in the end of August and the beginning of September the town of Kazanlak hosts the days of Thracian culture.