Seč Quarry near Rudice: Colourful Sands, Geological Organ Pipes and the Rules for Visiting

Seč Quarry near Rudice is a former sand pit where glass-making and foundry sands were extracted until 1993. Its walls shift through white, yellow, ochre, orange and deep red, and visitors often compare it to the Rainbow Mountains of Iceland. For geologists, it is the only surviving profile of the Rudice Beds in the Moravian Karst: sands and clays from the Lower Cretaceous that filled deep karst depressions in the limestone, known as geological organ pipes. Since 2022 it has been a nature monument. Entry is free, but you must keep to the marked path. Going up to the quarry walls is not allowed, nor is digging into the slopes or hunting for geodes with a spade, and lighting fires and camping are also banned. There is a pay car park run by the village of Rudice above the quarry.

QUICK LINKS 🎨 Why the quarry is so colourful · 🪨 The Rudice Beds and geodes · 🕰️ A brief history of quarrying · ⚠️ The rules · 🚗 Getting there · ❓ FAQ

For a long time, Seč Quarry was known mainly in Rudice itself. It was a working quarry area and entry was prohibited, though people came anyway. Since 2024 it has been made visitor-friendly, with information boards and a path leading all the way from the top down to the water. It is one of the few places in the karst where you can see what lies above the limestone rather than in it.

Why the quarry is so colourful

The colours come from kaolin and iron compounds. The upper layers hold white quartz sands, with reddish ferruginous sandstones alongside them. The red and brown layers in the lower parts of the walls reveal the presence of iron.

According to press reports, the quarry covers around 18,000 m². There are small pools on the quarry floor where amphibians live. Nature has swiftly begun to reclaim the quarry since quarrying ended.

The Rudice Beds, geological organ pipes and geodes

At the start of the Cretaceous, the limestone surface lay exposed, and in the tropical climate it turned into karst with rock towers and deep chasms. Sands, clays and fragments of chert were then washed into these hollows, and so the Rudice Beds were formed. The deep infills in the limestone are known technically as geological organ pipes.

According to the Protected Landscape Area Administration, Seč Quarry shows all this as nowhere else in the karst:

• The profile of the Rudice Beds is the only one preserved in the whole of the Moravian Karst.
• Limestone towers rise out of the multicoloured sands in the southern and south-eastern part of the quarry.
• Limonite forms coatings and crusts where it meets the limestone. It was precisely from the iron ores of the Rudice Beds that iron was smelted here for centuries.
• Quartz geodes, hollow spheres with crystals inside, are found in kaolinised layers known as běliny (bleached zones). There is more in the article Rudice geodes.
• Fossils. On the edge of the quarry there are outcrops of limestone containing corals, stromatoporoids and brachiopods, and fossilised Jurassic sponges have also been found in the strata.

A brief history of quarrying

Around Rudice, iron ore from the Rudice Beds was already being mined in prehistoric times, and there were large smelting works here in the 8th and 9th centuries. Mining was at its most intensive in the 18th and 19th centuries, using shafts between 20 and 140 metres deep, until 1893, when the deposits were exhausted. After that, only clays and sands were extracted, for ceramics, foundry moulds and glass. I write about the smelting industry in the area in the article Iron Karst.

Seč is an open-pit quarry for glass-making and foundry sands. Quarrying there ended in 1993. For a long time, locals came here for fine sand for plastering. Today the entrances are blocked off. In 2022, the Nature Conservation Agency (AOPK) declared the quarry the Rudice-Seč nature monument. It protects not only the geology but also seasonal pools, the stag’s-horn clubmoss (Lycopodium clavatum) and the European fire-bellied toad (Bombina bombina). The quarry is managed by the Mendel University Forest Enterprise.

The rules for visiting

The quarry is a nature monument and nature wardens carry out checks. According to the Protected Landscape Area Administration and the quarry’s manager, the following rules apply:

• Keep to the marked path. Do not go near the foot of the walls or the top edge, as there is a risk of landslides. Climbing on the walls is prohibited.
• No digging. Scraping at the slopes and digging pits is prohibited. According to the Protected Landscape Area Administration, you may take a geode you come across lying loose, but not dig or search with a spade. You risk a fine.
• No fires, camping or large groups.
• Swimming and building sandcastles on the quarry floor are fine, according to the Protected Landscape Area Administration.
• Dogs are allowed, but please clean up after them.
• Toilets are only at the car park above the quarry. According to the Protected Landscape Area Administration, there will be no snack bars or stalls here, but you will find refreshments in Rudice.

You will find the general rules for the Protected Landscape Area in the article Rules of the Moravian Karst Protected Landscape Area.

Getting there and what to combine it with

• By car: the pay car park run by the village of Rudice above the quarry (the U hrušky car park), north-west of the village.
• On foot: the Rudice Mines educational trail runs around the quarry. From the car park, you descend into the quarry along a maintained path.
• Rudice: a windmill with a museum and information centre, see Rudice.
• The Rudice Sinkhole is close by. It is a different protected site: a national nature monument where the Jedovnický stream disappears underground.

FAQ

Is entry to Seč Quarry free? Yes, entry is free. You only pay for parking run by the village of Rudice.

Can I look for a geode in Seč Quarry? You may take a geode lying loose. Digging and searching with a spade is prohibited.

Is swimming allowed in Seč Quarry? According to the Protected Landscape Area Administration, swimming on the quarry floor is fine. Fires and camping are prohibited.

Why is Seč Quarry so colourful? The colours come from kaolin and iron compounds in the sands of the Rudice Beds.

Information verified as of 13. 10. 2026. Sources: AOPK ČR, Analyses of the Moravian Karst PLA (2017), site no. 44 and the chapter on mineral extraction; L. Slezák, Geological Guide to the Moravian Karst (the Rudice Beds around Rudice); AOPK ČR Regulation on the Declaration of the Rudice-Seč Nature Monument (2022); Novinky.cz: Seč Quarry Awaits Tourists (4. 12. 2023) and The Colourful Sands of Seč Quarry (2. 9. 2024), both with comments from Antonín Tůma of the Protected Landscape Area Administration; Kudy z nudy: Seč Quarry near Rudice.

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