The Temple of Jupiter is located just west of Peristil, at the end of a narrow passageway called Kraj Sveti Ivana accessible between the Skočibučić-Lukaris and Cipci Palace. Originally, there were three temples to the right of Peristil; Kibel, Venus, and Jupiter however, only the latter remains today.

The Temple of Jupiter was built around the 3^rd century, about the same time is the palace itself. Jupiter was the name of Diocletian’s father and was also the highest Roman god, the god of the sky, and the god of thunder. This god was highly worshipped during the Imperial era until the Roman Empire came under Christian rule. Emperor Diocletian believed he was a reincarnation of Jupiter and thus positioned this temple directly adjacent to his mausoleum, not St. Domnius Cathedral.

The Temple of Jupiter is a miniscule rectangular temple with a very characteristic vaulted ceiling featuring a myriad of stone blocks, each with a different central motif. Boarding the ceiling and walls is a very ornate frieze all around. The temple is elevated as below it hides the crypt, which is a typical character of a Roman temple. The doorway features very intricate moldings that tell a story in itself. It is considered to be one of the best-preserved Roman temples in the world.

At the fall of the Roman Empire in the Middle Ages, the temple was converted into Saint John’s Baptistery (Sv. Ivan Krstitelj), named after the Archbishop of Split. This meant the addition of large 12^th century baptismal font, which allowed for total immersion according to the Byzantine rite. Carved on the font is previous Croatian King Zvonimir and other notables at the time. Today, the font is used by visitors who make a wish by tossing in a coin.

Along the back wall are two medieval stone tombs where the remains of Bishop John (8^th century) and Bishop Lawrence (11^th century) lie. In between the two coffins is a large statue of John the Baptist by famous Croatian sculptor Ivan Meštrović.

Outside the entranceway lays a Roman sarcophagus and guarding the temple is a headless graphite sphinx (from 1500 BC), which Diocletian brought from Luxor. Directly next to the temple is Split narrowest street called “Pusti me proć,“ meaning let me through.

The temple is largely closed during the winter months however, they are open during the long tourist season and admission only costs 5KN.

This Cathedral of St. Domnius (Katedrala Sv. Duje or Sv. Dujam) is the most visited attraction in Split, particularly as the imposing bell-tower is considered the emblem of the city. The church was originally built as Diocletian’s mausoleum; quite an oxymoron as the emperor was a known prosecutor of Christians. It was converted into a cathedral in the mid 7^th century and the central place originally meant for Diocletian's sarcophagus was ritually destroyed.

The original octagonal shape of the mausoleum has been almost completely preserved although the domed ceiling no longer bears glittering mosaics. 24 columns surround the exterior of the structure and the domed interior is encircled with two rows of intricately decorated red granite Corinthian columns. The circular crown in the dome separating the two rows of pillars features detailed carvings of cupids, masks and human heads. There is a frieze showing the emperor with his wife, Prisca as well as four semi-circular and four rectangular niches.

Local artist Andrija Buvina carved two wooden cathedral doors in 1214 AD, which are still in place today. The fascinating Romanesque handicraft showcases 14 images illustrating the life of Jesus Christ with elements of gold plating.

The altar on the right is dedicated to Saint Domnius, a Christian martyr and 3^rd century Bishop of nearby Salona (Solin). He was prosecuted under the rule of Diocletian. It is decorated with frescoes and its altar ciborium, or cup, are both in the late Gothic style. The altar to the left is constructed by famed Croatian architect Juraj Dalmatinac in the 15^th century and is dedicated to another martyr and patron saint of Split, Anastasius

Left of the entrance is a six-sided podium in a precious green stone constructed in the 13^th century. The main alter was built in the late 17^th century and bears beautiful carvings of ten scenes from the old Testament. Another alter built in the late 18^th century features relics of Saint Domnius. A chorus was added to the eastern side of the mausoleum with benches carved in the early 13^th century.

The most apparent part of the cathedral is the 57-meter belfry towering high above the palace. Construction started in the 13^th century and supposedly went on for 300 year until completion. It is designed in the Romanesque style although details from other architectural eras were incorporated throughout its many years of construction. An arched portal cuts through the bottom of the tower to the entrance of the cathedral. At the foot of the tower are two stone carved lions that guard the entrance at either side. Above the portal is a little sarcophagus containing the remains of two daughters of a previous king who died of the plague in the 13^th century. It is possible to climb to stairs to the top of the tower where breathtaking 360-degree views of the city will welcome you.

In the adjoining sacristy building, you can also access the treasury containing sacral art works, 13^th century chalices and containers, ancient garments and books dating back to the 6^th century. Below the cathedral is the crypt, which was turned in to the Chapel of St. Lucy (Sv. Luce) during the Middle Ages.