The oldest nucleus of Split is located within the walls of Diocletian's Palace. According to its dimensions and level of preservation, the Palace represents the most valuable example of Roman architecture on the eastern coast of the Adriatic Sea. It was constructed around AD 300 and has a rectangular ground-plan. Its form and arrangement of the buildings within the Palace represent a transitional style of an imperial villa, Hellenistic town and Roman camp.

 

The Roman Emperor Diocletian spent his declining years in an enormous palace that he had built near his birthplace, Aspalthos, in Dalmatia. With the passing centuries the original architecture of the palace has been altered, but the people of the city, later called Spalato, and then Split, were able to use the structure of the palace, damaging it as little as possible, under Byzantine, Venetian and Austro-Hungarian rule. Thus, a harmonious city came into being within the Roman walls. The peristyle of the palace, Diocletian's mausoleum, Jupiter's temple, the colonnades along the streets, Early Croatian churches, Romanesque houses, the gates of Andrija Buvina and architectural works by Juraj Dalmatinac have remained in a good state.

 

The southern, seaward side of the Palace (181 m long), with subsequent annexes, can be viewed from the coast. The Brass Gate (Porta Aenea), a vaulted passage leading from the sea into the interior of the Palace, are in the middle of the southern side. To the left is the entrance into the cellars of Diocletian's Palace, with a system of corridors and halls under the southern parts of the Palace which can be visited by tourists.

 

Walking along the eastern side of the Palace one reaches the Silver Gate (Porta Argentea) with the church of St. Dominic on the opposite side, which was first mentioned in the 13th century. Its present aspect dates from 1682, and it was reconstructed between 1932 and 1934; it contains Baroque altars, the paintings representing the Miracle in Surian (Jacopo Palma the Younger) and The Apparition in the Temple (Palma's school), and a wooden Gothic cross. Through the Silver Gate one reaches the Plain of King Tomislav. Passing by the small Renaissance church of St. Roch (Rocco) (1516) one arrives to the Peristyle (Peristil), the central open-air area of the Palace. Its longitudinal sides are surrounded by an arched colonnade; the arches in the west are closed by Gothic and Renaissance houses. A monumental port with four columns carrying a gable closes the Peristyle in the south. Between the columns of the entrance two chapels were built in, Our Lady of the Belt (1544) and Our Lady of Conception (1650).

 

The mausoleum of Diocletian, today's Cathedral of St. Doimus (Dujam) (dedicated to St. Mary) lies in the eastern part of the Peristyle. The mausoleum has almost completely preserved its original octagonal form, encircled by 24 columns (peripteral) which were bearing the roof; the interior is round, with two rows of Corinthian columns and a frieze (medallions with figures of Emperor Diocletian and his wife Prisca). A dome, once covered with mosaics, roofs the mausoleum. The monumental wooden gateposts (reliefs with scenes from the life of Christ), a work by Andrija Buvina (1214), and the stone pulpit from the 13th century represent the oldest monuments in the Cathedral. The altar on the right, with a late Gothic baldachin, was made by Bonino da Milano (1427). The vault above the altar is decorated with mural paintings, a work by Dujam Vuskovic (15th c.). the altar of St. Anastasius (Stas), made by George of Dalmatia (Juraj Dalmatinac) in 1448 is to the left (the predella features an excellent central scene of the Flagellation). The chapel in the northern wall accommodates the Baroque altar of St. Doimus, a work by the Venetian sculptor G. M. Morlaiter (1767); the vault of the chapel is decorated with paintings by M. Capogrossa. The main altar dates from the 13th century; the vault above it is ornamented with paintings by M. Poncun; a wooden Gothic cross from the 14th century rises above the altar. The choir, constructed in the 18th century, is furnished with Romanesque seating from the 13th century (the oldest in Dalmatia) and ornamented with a painting re-presenting the Mother of God with the saints and donors, a work by J. Palma the Younger, as well as with Baroque paintings by M. Poncun. A crypt lies under the Cathedral. A building with a sacristy and treasury leans on the Cathedral. The treasury keeps a collection of gold artefacts and mass vestments from the Romanesque, Gothic and Baroque per-iods; the most valuable pieces include a ciborium from 1522, the 8th-century evangelistary (the oldest manuscript in the country), the 11th-century Supetar chartulary and Historia Salonitana by Thomas the Archdeacon from the 13th century. Three Romanesque reliefs from the 13th century were built into the foot of the belfry towards the main entrance; the peripteral construction accommodates several sarcophagi from the 9th to the 15th centuries. The Romanesque belfry was erected between the 12th and the 16th centuries, collapsed at the end of the 19th century and reconstructed in 1908. Two Romanesque lion figures lie at the foot of the belfry, and the right wall is decorated with an Egyptian black granite sphinx (15th c. BC).