The Tomb of Leonidas has an impressive edifice (12.5m × 8.30 m), probably dating back to the late 5th century BCE. It was made of massive limestone and its interior was divided in two connected chambers. The eastern chamber was 3.15 meters long, had the form of a pronaos (vestibule) and was ornate with columns. Until today, the use of the edifice has not been verified.It is believed to be a cenotaph, while many researchers share the opinion that it is the temple of Karneios Apollo.
Although there is no indication on the correlation between the temple and the legendary king of Sparta, according to local tradition and the travel writer Pausanias, the remains of Leonidas were transferred and buried there. It is because of this, that the locals believe it to be the tomb of Leonidas. Pausanias also mentions that annual games were hosted here to honor the memory of the Spartan king.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.