Diocletian's Fish Pond in Nečujam – a Roman site hidden in the shallow waters of Piškera Bay

Diocletian's Fish Pond is located in Piškera Bay, one of the smallest and most deeply recessed bays within the larger Nečujam Bay. It is not a landmark that can be seen from the road like a church or an old stone house. The most significant part of the site lies underwater at the entrance to the small bay, meaning many visitors pass by unaware that they are looking at the remains of a structure nearly two thousand years old.

In Nečujam, it is commonly referred to as Diocletian's Fish Pond, a name used by the Šolta Municipality, tourism and media sources, as well as project documentation related to the site's protection. However, it is important to distinguish what has been archaeologically confirmed from the stories passed down through generations. It is reliably confirmed that there was a large ancient fish pond, or Roman piscina vivaria, intended for the storage and breeding of live fish in Piškera. Direct evidence that the pond personally belonged to Emperor Diocletian has not yet been found. Therefore, it is most accurate to say that it is a Roman fish pond known as Diocletian's Fish Pond.

The name Piškera is associated with the Latin word piscina, meaning pool or fish pond. In antiquity, almost the entire end of the bay was separated from the open sea by a large stone wall. In the middle of the wall, there was a passage about three metres wide, closed off by a special barrier that allowed seawater to flow in but prevented fish from escaping. This way, live fish could be kept in the naturally sheltered and shallow bay until needed by the residents of the nearby villa or for supplying other locations.

The remains of the wall and embankment are now submerged, but they can still be discerned beneath the surface in calm waters. The site extends approximately 70 by 10 metres, with a depth of around three to five metres in the area. The waters in Piškera are generally calm, with weak currents and good visibility, making the wall most visible on sunny days when there are no waves and when viewed from above or with the aid of a snorkel. Diving is permitted, but the remains must not be touched, moved, or used for anchoring, as it is a protected underwater archaeological site.

Adjacent to the fish pond was a Roman villa, likely of the villa maritima type, which was a coastal agricultural estate. Archaeological literature indicates that the villa was located right by Piškera, but it has not yet been systematically researched. Such villas were not merely places of rest for wealthy owners; they managed agricultural estates, wine and oil production, fishing, maritime trade, and the supply of ships and surrounding settlements. In the immediate hinterland of Nečujam, there are fertile areas suitable for vineyards and olive groves, so the location by a safe bay also had economic significance.

The connection of the site to Diocletian is primarily based on local tradition, the time of the pond's creation, and its proximity to Split, where the emperor built his palace in the early 4th century. Šolta documents and tourist interpretations suggest that Diocletian stayed in Nečujam and used the bay as a fish pond, with occasional mentions of baths. However, archaeological sources speak more cautiously about the Roman fish pond and note that the bay is popularly referred to as Diocletian's Fish Pond. Therefore, it is best to retain the well-known name for the article, but not to assert that Diocletian's ownership is conclusively proven.

Visiting the site is now much simpler than before. Around Piškera Bay, a thematic walking path approximately 400 metres long has been established as part of the "Eco Šolta – Below and Above" project. During this project, the seabed was cleaned, the coastline was arranged, and access to the site was improved. The path follows the calm edge of the bay and allows views of the submerged wall from multiple points, while interpretive signs help visitors understand what lies beneath the surface of the sea.

Piškera is located about one and a half kilometres from the main part of Nečujam and the central beach. It can be reached on foot, by bicycle, scooter, or car via the local road through the settlement. Walking is more pleasant outside the hottest part of the day, as the route involves some ups and downs through the rugged area of Nečujam. Accommodation facilities in the bay indicate a distance of about 1.5 kilometres to the centre and shops, which is a useful guideline for planning your visit.

There is no large public parking area near the bay. Space is limited, the road is narrow in places, and some areas near houses are reserved for local residents and accommodation guests. It is best to leave your car in a safe widening without blocking access to houses and continue the last part on foot. During the main season, a scooter, bicycle, or walking from Nečujam is more practical.

No ticket or specific opening hours are required for viewing, as the site can be observed from the public shore and path. The best times to visit are in the morning or later in the afternoon when the sun is at a more favourable angle and the underwater wall becomes more visible. For a closer look, a mask and snorkel are useful, but one should not enter among the moored boats or swim through their navigable passage. The bay has local moorings, and the central opening through the ancient wall must remain passable for smaller vessels.

Diocletian's Fish Pond is not a spectacular site in the classical sense. There are no high walls, large columns, or restored Roman rooms. Its value lies precisely in the fact that the original structure remains where it was in antiquity – between land and sea. When the line of the stone wall beneath the surface is recognised from the shore, it becomes clear that the tranquil Piškera Bay is not just a place for swimming and mooring boats, but one of the most interesting traces of Roman life on Šolta.