"The Cathedral Basilica of St. Dionysius the Areopagite"

The church is a three-aisle basilica in the neo-Renaissance style. The German architect Leo von Klenze drafted the plans for the cathedral at the behest of King Otto of Greece. The architecture is influenced by St Boniface's Abbey in Munich. During the project, the plans were modified by the Greek architect Lysandros Kaftanzoglou.

The church is 38 metres long, 15 metres high and 24 metres wide. The church's interior is decorated with beautiful frescoes. Of the most beautiful is the fresco of semi-domes of triumphal arch, representing the Apotheosis of Saint Dionysius the Areopagite (1890) and is the work of Italian painter from Rimini Guglielmo Bilancioni (1836–1907). The pillars, which support the triumphal arch, represent in life-size the four Evangelists. In front of the triumphal arch is depicted Christ Pantocrator with the Gospel in hand. In the adjacent corner on the right is Moses holding a parchment, and on the left the Prophet David playing a harp. Below are Saint Gregory the Great and Saint Augustine. The church floor is paved with Pentelic marble. The nave is supported by 12 columns of 5 metres of green marble from Tinos.

Right and left of the main entrance are two inscriptions, one in Latin, the other in modern Greek, commemorating the Athenian visit of pope John Paul II in 2001