Bottini of Siena: visiting the town’s underground aqueduct

Bottini of Siena: the town's underground aqueduct

The Bottini of Siena are a network of underground water galleries that supplied the medieval town. Stretching for more than 25 km beneath the historic centre, they are an important example of traditional hydraulic engineering linked to the life and growth of the town.

What they are and why they matter

These are hand-dug tunnels carved into tuff and clay soils, built with precise gradients to channel water by gravity. Water filtered naturally through the ground and fed public fountains, enabling Siena to thrive despite the absence of a nearby river.

Visit routes

The network includes main and secondary channels; some sections are open to the public through guided tours that explain construction techniques, marks left by workers and the hydraulic functioning. Tours are run in small groups to protect the fragile underground environment.

How to book and tickets

• Limited access: visits are restricted to a limited number of annual entries (approximately 1,000 visitors in total), so advance booking is required.
• Small groups: entry is usually organised in groups of up to 10 participants, led by experienced guides.
• Indicative fees: full ticket around €20; reduced tickets (students, over 65, residents, specified age groups) around €10. School groups from the municipality and very young children may be free, although the visit is generally not recommended for under‑8s.
• Reservations: bookings are handled via municipal services; requests are processed in the office hours indicated by the Comune and payment is normally required in advance.

Practical tips for visitors

• Wear comfortable closed shoes; underground sections can be damp and slippery.
• Bring a light jacket: temperatures below ground are typically cooler than on the surface.
• Mention any mobility issues: some stretches include narrow passages or steps.
• Respect the site: follow the guide's instructions to avoid damaging historic structures and deposits.

What to see in the town after the visit

After touring the Bottini, take time to visit other highlights of Siena's historic centre:

• Piazza del Campo – the shell-shaped square, the civic heart of the town and stage of the Palio.
• Siena Cathedral (Duomo) – a masterpiece of Italian Gothic with distinctive striped marble interiors.
• Santa Maria della Scala complex – the former hospital now transformed into a cultural hub with exhibits that narrate local history.
• Water Museum – an ideal stop to deepen your understanding of the underground network and the historical bond between the town and water.

Why include the Bottini in a visit to the town

Visiting the Bottini offers insight into a crucial part of Siena's social and economic past: the management of water and the clever solutions developed by residents to make the historic town sustainable. It enriches a visit to the town with a lesser-known yet essential perspective.