Maciço Calcário Estremenho
Nascente do Almonda (Torres Novas)
Info · exploration
Closed: access through the Renova dam only with permission, which is not given at the moment; only exploration teams dive here.
- Max depth115 m
- CertificationFull cave
- SpecialExperienced divers
Diving and fills
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Now at Nascente do Almonda (Torres Novas)
The dive
The Nascente do Almonda is the source of the Almonda river in Vale da Serra, inside the Parque Natural das Serras de Aire e Candeeiros.
Part of Gruta do Almonda. Also in this system: Almonda Norte (Vale da Serra)
Profile and sections
The Nascente do Almonda is the source of the Almonda river in Vale da Serra, inside the Parque Natural das Serras de Aire e Candeeiros. Behind it lies Portugal's largest known karst network, more than 15 km long: several underground streams that together feed the spring.
The Gruta do Almonda has two entrances: this spring and Almonda Norte, further north inside the cave. In 2011 XploraSub and the Núcleo de Espeleologia da Universidade de Aveiro mapped the underwater galleries at the spring; AESDA published a survey of them in its magazine Trogle 7. The cave beetle Trechus lunai lives in the cave, there are archaeological sites from the Lower Palaeolithic to Roman times, and since 1993 it has been protected as an Imóvel de Interesse Público.
Practical: Renova fenced off the site some years ago. Whether the spring water is private or public is disputed locally; in 2024 the Torres Novas municipal assembly asked for the site to be laid out and opened to everyone.
- Depth and profile
- More than 2 km of underwater galleries; the greatest known depth is -115 m (AESDA and XploraSub, 2025). The deep part of the Gruta do Almonda is reached through Almonda Norte.
- Configuration
- Not published.
Who can dive where
- At least Full cave
- Configurations: Backmount / twinset / Sidemount / CCR / Small cylinders / no-mount (speleo sumps)
- Configuration unknown — research beforehand
- Goes down to 115 m (trimix or deco may be needed)
- Experienced divers only
This is how the planner decides who in your team may dive this cave. Rules your own trip adds (organizer, a mail, the AI) show with your trip.
How to get there
Through the Renova dam, by the paper mill that draws water there and regards the site as private. Permission is needed, and access is currently closed (AESDA, Nov 2026).
Around Nascente do Almonda (Torres Novas)
FillsNo fill station known nearby
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