Although the early data of Aizanoi are materials dated to the Paleolithic age, the earliest archaeological data belonging to a settlement were obtained from the mound on which the temple of Zeus was located and goes back to the Early Bronze Age. The heyday of Aizanoi is the Roman Imperial Age. Especially during the Hadrian’s and Antonine Dynasties, the increasing development activities and the fact that it became a city that received intense immigration enabled Aizanoi to gain a cosmopolitan structure. In this period, Ulpius Appuleius Eurykles, one of the wealthy families of the city, the most prominent name of the Ulpius, undertook the financing of the development activities in the city. Until the middle of the 3rd century AD, it was one of the leading cities of the region with its political and religious position. At the beginning of the 4th century AD, Phrygia, which was a combination of Phrygia and Caria, became part of the Prima Province. The city, which was the episcopacy center in the Early Byzantine Period, also sent its bishops to various cities. After the 8th century AD, it gradually lost its importance. In the 12th and 13th centuries AD, the Çavdar tribe from the Tatar tribe settled here, turned the temple into a castle and gave the region its current name. After the Byzantine emperors lost control of Western Anatolia, Aizanoi became a part of the Germiyanoğulları Principality, whose center was Kütahya and which flourished in the last quarter of the 13th century and the beginning of the 14th century.

The first information about Aizanoi was conveyed by travellers who came to the region during the 19th century. The first scientific studies were carried out by German scientists in 1926 and 1928, continued intermittently within the German Archaeological Institute since the 1970s, and finally, 2011 excavations and research began to be carried out on behalf of Pamukkale University with the permission given by the Ministry of Culture and Tourism. Aizanoi is an example of cultural heritage with its ancient texture, which contains examples of public and religious architecture, and its rural structure, which includes examples of local civil architecture from the Turkish period, and its population that continues to live here. With these features, it was accepted into the UNESCO World Cultural Heritage Tentative List on 12 April 2012.

A project with this name has been prepared with the aim of archaelogical studies carried out in Penkalas/Kocaçay Stream since 2012, to clear the fill formed between bridges 2 and 4, keeping the tea bed in its original borders, and improving the relations with the surrounding tissue and developing tourism together with navigable areas. This project has been submitted to the Kütahya Conservation Board. Then, with the decision of the Kütahya Cultural Heritage Preservation Regional Board Directorate dated 19.06.2017 and numbered 4081, the “Penkalas/Kocaçay Stream No. 2-4 Bridge Improvement Project” was approved.

Rural tourism, which is compatible with the concept of sustainable tourism, has a feature that can be carried out together with culture, history, environment, agriculture and tourism, but it is a type that integrates especially with eco-tourism. Aizanoi-Çavdarhisar and its surroundings, both its ancient texture and nature, and the Penkalas Stream passing through it, walking along the creek and paths, walking in the countryside along the edge of the creek extending to the ancient city and the Cybele Sanctuary, seeing all the colors that nature offers to Aizanoi without hesitation, and watching the rural landscape are the same. At the same time, it is one of the rare settlements in terms of offering the opportunity to taste the fresh and natural products of the region and to experience the rural culture.

As the project approach criterion, it is aimed to make the data of nature, civil architecture and ancient period perceptible and livable with the touches that will strengthen the environmental relations with the least interference to the current situation. The sine qua non of this approach is that all proposed interventions regarding both restoration and environmental use are removable/retrievable/returnable.

The Penkalas River archaeological study and the Penkalas/Kocaçay River Rehabilitation Project between No. 2 and 4 Bridges started in 2012 and are still continuing. Within the scope of these studies, the first stage was environmental cleaning, documentation of architectural blocks and measurement studies. The second stage was the cleaning of the stream floor with the help of DSI and documenting the removal of architectural plastics in the stream. The third stage, it is aimed to make static measurements of the protection walls on the banks of the stream and to strengthen them to the required extent.

In all the interventions made until the end of the 2020 works, it was tried to protect the original architectural features of the walls in the project in question, and the historical texture, patina and originality of the interventions were tried to be preserved when viewed from the outside. No part of the flood/set walls has been dismantled, except for the completion. During the completion, the original blocks identified and inventoried in and around Penkalas were used. Thus, significant progress has been made in this project, which is one of the most important tourism values of Çavdarhisar and Kütahya, and many obstacles have been overcome before the project is completed and opened to regional tourism.