Třeboň · Fishponds
The fishponds around Třeboň
TřeboňRožmberk 426 m above sea level
Rožmberk · Svět · Zlatá stoka · Fish harvests
The fishponds of the Třeboň area are not nature. They are structures: dams, outlets and kilometres of canals built by fishpond engineers from the late 15th century onwards. That is why they show so clearly how a landscape works.
Four fishponds in figures
| Fishpond | Area | Dam | From the square | Character |
|---|---|---|---|---|
| Rožmberk | 647 ha (water surface 489 ha) | 2,355 m | ≈ 6 km north | The largest in Czechia, a monumental dam |
| Velký Tisý | 317 ha | 1,850 m | ≈ 10 km north | The fifth-largest in Czechia, a bird reserve |
| Svět | 201.5 ha | 1,400 m | ≈ 1 km south | The town fishpond, the evening promenade |
| Opatovický | 160.6 ha | 1,177 m | ≈ 1 km south | An island, a beach, one of the oldest |
Why two figures for Rožmberk? Its cadastral area is 647 ha, but at normal water level “only” 489 ha is under water. The difference is a reserve for floods – the fishpond protects the Třeboň area against flooding.
Rožmberk
It was designed by the Rožmberk family’s regent Jakub Krčín and built in 1584–1590. 800 people worked on it and moved 750,000 m³ of earth. Originally it covered around 1,060 ha and swallowed up the neighbouring Vítek fishpond.
The dam is 2,355 metres long, 55–60 m wide at the base and about 12 m high. A path runs along the crest, with a view across the whole fishpond. To keep floods from the Lužnice from destroying the fishpond, Krčín built the Nová řeka (“New River”) at the same time: a 13.5 km canal that diverts high water into the Nežárka.
How to get there: from Třeboň on the Rožmberk nature trail (a 22 km loop) or via Nová and Stará Hlína.
Svět
The fishpond on the southern edge of town, exactly on the 49th parallel, a kilometre from Masarykovo náměstí. Its dam, which bends twice, measures 1,400 metres. Lázně Aurora stands on one side and the Schwarzenberg Tomb in its park on the other. In the evening the dam is where most of Třeboň can be found.
The Cesta kolem Světa, a path of about 11 km, runs all the way round – the best first walk or ride.
The Opatovický fishpond
One of the oldest fishponds in the area, right next to Svět. In the middle lies a wooded island inhabited only by waterbirds. On the northern edge there is a holiday centre with a small beach, and there is another beach at Doubí. The Okolo Třeboně nature trail runs along the dam.
The canals: Zlatá stoka and Nová řeka
The Zlatá stoka (“Golden Canal”) is a 45 km canal built in 1508–1518 to a plan by Štěpánek Netolický. Its gradient is only about 69 cm per kilometre. It still brings water to and from the fishponds and runs through Třeboň past Bertiny lázně. It was only called “golden” under the Schwarzenbergs, because of its importance for fish farming.
The Nová řeka is a 13.46 km artificial canal between the Lužnice and the Nežárka, built to protect Rožmberk.
Fish harvests
The main fish-harvest season (výlovy) is in autumn. Rybářství Třeboň usually publishes the dates in mid-September. Smaller harvests also take place in spring. The traditional highlight is the Rožmberk harvest, with a programme of events on the dam.
2026: According to Rybářství Třeboň, the ceremonial Rožmberk harvest is not taking place because of an unfavourable water balance. Instead, “Days with the Třeboň fishermen” are being held on 16 and 17 October 2026.
Map of the area
Frequently asked questions
Can you swim in the Třeboň fishponds?
The fishponds are used mainly for fish farming. You can swim at designated places – for example at the beach of the holiday centre on the northern edge of the Opatovický fishpond. In summer, the regional public health authorities monitor water quality.
When is the Rožmberk fish harvest?
Traditionally in mid-October. In 2026 the ceremonial harvest is not taking place because of an unfavourable water balance. Instead, Rybářství Třeboň is holding “Days with the Třeboň fishermen” on 16 and 17 October.
Read on
Plan the trip
Three helpers, already set for Třeboň. All of them are also on the Planner page.
How we chose
- We wrote about Třeboň because it works as a base for a stay: there is somewhere to sleep, something to do on foot or by bike, and a way to get there.
- Facts such as areas, dates and rules come from official bodies and Wikipedia. Each one is in the source list below, with the date we last checked it.
- We name no individual hosts, and nobody pays to be included.
Sources (8) checked on
- Rožmberk – Wikipedia (in Czech) – 647 ha, water surface 489 ha, dam 2,355 m, 1584–1590
- Svět (fishpond) – Wikipedia (in Czech) – 201.5 ha, dam 1,400 m, 436 m above sea level
- Opatovický fishpond – Wikipedia (in Czech) – 160.6 ha, dam 1,177 m
- Velký Tisý – Wikipedia (in Czech) – 317 ha
- Zlatá stoka – Wikipedia (in Czech) – 45.2 km, 1508–1518
- Nová řeka – Wikipedia (in Czech) – 13.46 km
- Ceremonial harvest of the Rožmberk fishpond – Rybářství Třeboň (in Czech)
- Fish harvests – Rybářství Třeboň (in Czech)
Where a source is only in Czech, it says so. How we pick sources and fix errors: About the atlas.