There is a massive fortress surrounded by the Rhodope Mountains right on the way from the city of Plovdiv to Asenovgrad. Its oldest stones date back to Thracian times, but little is known about the long history of the Bulgarian Fortress of Asen. It reached its peak in the Middle Ages. Then this place was called Petrich. It got its present-day name "Asen's Fortress" in the 13th century during the reign of Tsar Ivan Asen II. At this time, the ancient defensive walls underwent significant changes to protect the Kingdom of Bulgaria from the invasion of the Latin Empire. Up to 12 meters high and more than 3 meters thick, solid stone walls have defended the fortress for many centuries. Today, there are 30 preserved rooms and 3 water storages. Besides, a monument to the Bulgarian Tsar Ivan Asen II rises in Asenovgrad.

The only formidable enemy that captured the citadel was the Byzantine Empire. However, it happened after the death of Ivan Asen II. Later, the impregnable walls were repeatedly besieged by the Turks. Fearless warriors of the great Ottoman Empire had quickly lost interest in the ancient fortress, so it emptied soon. There was only one building that continued to be moving through life, the Church of the Holy Mother of God.

This magnificent monument of sacred architecture was erected within the fortress almost immediately after the construction of the defensive walls in the 12th-13th centuries. A couple of centuries later, the two-story church with spacious arched windows was decorated with frescoes, some fragments of which can still be seen today. In addition, the old church is notable for being one of the first religious buildings, the church tower of which served both as a bell tower and an observation post. Today, its top offers a fabulous view of the fortress and the town of Asenovgrad. Today, the fortress and all the buildings, including the ancient church, are open to the public and are among the main tourist attractions.