Gruta Casa de Pedra: largest cave mouth in the world
Gruta Casa de Pedra or the House of Stone Cave is a cave located in the Alto Ribeira Tourist State park, Brazil. It is 1.8 miles long and has the largest cave mouth in the world, which is 564.304 ft high. The complex of caves were formed thousands of years ago.
The Historic Center of Tiradentes is well known for its cobblestone streets, cute little houses, restaurants and churches. But, for some visitors mainstream tourists routs are not appealing. If that’s the case, an ecotourism is your best bet. Visitors can choose from various types of activities, such as: hiking, paddle boating, exploring caves and visiting waterfalls. The Stone House Cave is conveniently located between Tiradentes and São João del Rei.
The Gruta Casa de Pedra is a limestone cave, with a river flowing through it. Obviously, it has a lot of speleothems. The curtains and columns of stalactites and stalagmites give the cave otherworldly beauty. Also, other interesting geological formations, such as the pulpit and the royal chandelier in one of the halls, give the cave a fascinating charm. The fauna and flora of the cave also enchants visitors. It has some openings, where it is possible for an ambient light to enter. Also, there are lighted points, so its easier to appreciate some of the main limestone formations. The tunnels of the caves have more than 1300 ft of extension and five enormous halls.
The tour does not take more than an hour and If you ignore the sound of bats, it will turn into a music to your ears and you’ll truly enjoy the beauty of nature.
UnusualPlaces Field Notes
- Location
- Casa de Pedra cave portal, PETAR, Iporanga, São Paulo, Brazil
- Coordinates
- -24.48169, -48.5915
- Access
- The São Paulo state park permits a guided visit to the cave portal exterior; entering the cave is prohibited for safety. The official trail is 4–5 km, moderate and takes 2 h 30 min–3 h. A park monitor is mandatory, advance booking is required, and daily capacity is limited to 80 visitors. The unit lists no accessibility for visitors with mobility limitations.
- Admission
- The park’s Casa de Pedra page lists R$19 for Brazilian visitors. The state tariff table lists PETAR general admission R$37, Brazil-discount R$19 and Mercosur-discount R$28; eligibility and current amount depend on ticket category, so confirm during booking.
- Time needed
- Allow 2 h 30 min–3 h for the guided 4–5 km Portal da Casa de Pedra exterior trail. This is not an interior-cave visit; entry is prohibited.
- Best season
- The park does not publish a preferred season for this trail. Rain can affect conditions in this cave and surrounding area; check the park’s current trail status, weather and guide/booking requirements before visiting. The cave interior remains closed to visitors.
- Opening hours
- The unit is open Tuesday–Sunday, 08:00–17:00. The portal trail lists departures at 08:00 and 10:00, with advance booking and a maximum of 80 visitors per day.
- Location checked
- 2026-09-27
- Facts checked
- 2026-10-08
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