Twenty five years ago on April 13, 1993 the Bulgarian archaeologist Georgi Kitov and his team discover the central chamber of the ancient Thracian burial mound (tumulus) Ostrusha near the town of Shipka. This tumulus placed among the most remarkable architectural achievements in the Valley of the Thracian Kings. The complex dates back to the time of the ancient city of Sevtopolis- the 4^th- the 3^rd century BC. It functioned until the end of the 4^th century AD. Five rectangular chambers and one circular chamber are situated in an area of 100 square meters. They were made of vey well-cut stone blocks firmly soldered by iron clamps and covered with lead. The tumulus was built by 2 monolithic stone blocks weighing 60 tons. Human portraits, animal figures and floral ornaments can be clearly seen at the precisely cut ceiling ornaments. According to archaeologists, some of the finds discovered in one of the biggest tumuli in the Valley of the Thracian Kings are unique. A horse skeleton, weapons, a silver jug, silver  decorations for horse trappings, a phial, coins dating back to PhilipII of Macedon, ceramic pots and other items with high artistic value were found at the Ostrusha burial mound.