Vela Placa, also known as the Great Square or Platea Magna, has been the main city square of Krk, likely retaining this role since Roman times. The Roman architect Vitruvius instructed that squares near city walls by the sea should be located close to the harbour, and if further inland, in the city centre. If no square existed previously, the Romans would have created one following this guideline. The square was undoubtedly more monumental in ancient times, extending further south towards the Small Gate. However, its exact dimensions and the structures that surrounded it during the Roman period await further exploration.

The square was first mentioned in 1263. During the Middle Ages, it remained the administrative centre of the city, hosting the city hall and two loggias, likely serving as the Roman marketplace and trading arcades. The square also housed a prison, which remained in use until the early 20th century. Historical documents reveal that the square consistently featured numerous workshops and shops over the centuries. In the late 15th century, the first Venetian Providur, Antonio Vinciguerra, initiated a comprehensive renovation of the city walls and square, replacing the old city hall with a new structure known as Torrion, which still stands today. 

The centrepiece of the square, the cistern crown of Providur Angelo Gradenigo, installed in 1997, was originally crafted in 1558. This hexagonal crown is the most significant example of carved Renaissance urban design on the island and in the broader Kvarner region. The crown is hexagonal and consists of six relief panels of different dimensions. Its six relief panels include depictions of the winged lion of St Mark with an open book, the city’s patron saint St Quirinus, and the coat of arms of Providur Angelo Gradenigo, as well as decorative elements and an inscription celebrating the providur’s success in defending the city against the Uskoks.

Beneath the square lies an archaeological site featuring remains of the oldest sections of the city walls, dating to the 4th or 3rd century bc, and a single-aisle Church of St Stephen the Protomartyr, believed to originate from the pre-Romanesque period.

The sturdy hexagonal late Gothic tower, strategically positioned at the junction of the western and southern sections of the city walls near the Small Gate, was commissioned in 1407 by Duke Nikola IV Frankopan. This is evidenced by an inscription and the Frankopan family coat of arms carved onto a fragment of a Roman stele (funerary monument) from the 1st century, affixed to the facade. The tower was part of a comprehensive effort to reinforce the city walls.