The Holy Temple of the Diocese of Tegea - dedicated to the Assumption of Mary - is located at one of the most important archaeological sites in Greece. The human presence was consistent, there are ancient findings, Hellenic, Roman and Byzantine. Remnants of a middle-ages castle have also survived. Essentially it is an enormous open archaeological site shaded by tall trees in a green park.

The original Byzantine church must have been built in the 11th or 12th century. It was the cathedral of the medieval town of Niklio. The church seems to have been built above the ancient theatre of Tegea, with materials taken both from the theatre and other nearby buildings, such as the early-Christian churches and the medieval wall that used to stand there.

After the decline of Tegea and its destructions by wars and earthquakes, the church remained in ruins until the 19th century. It was restored in the period 1884-1888 based on the study of the Austrian architect Ernst Ziller. Due to this restoration, the upper parts of the monument have been altered.

The church was not signposted and it took some effort to find its location. Unfortunately it turned out to be closed and there was no one who could help us with a key. As a result we were unable to see (and photograph) the interior with the religious paintings.