280 mm.
Photograph by Mike Peel (www.mikepeel.net). — CC BY-SA 4.0 · Photograph by Mike Peel (www.mikepeel.net). — CC BY-SA 4.0 · Photograph by Mike Peel (www.mikepeel.net). — CC BY-SA 4.0 · Photograph by Mike Peel (www.mikepeel.net). — CC BY-SA 4.0 · Photograph by Mike Peel (www.mikepeel.net). — CC BY-SA 4.0 · Photograph by Mike Peel (www.mikepeel.net). — CC BY-SA 4.0 · Photograph by Mike Peel (www.mikepeel.net). — CC BY-SA 4.0
The Andradas Fort, originally the Monduba Fort, is a fortification on Morro do Monduba in Guarujá, built with the Itaipu Fortress to defend Santos Bay and its port. It was designed in 1934 and building began in 1938 to protect the port during the Second World War; it opened on 10 November 1942 as the last fort inaugurated in Brazil, and was later named after the Andrada brothers. The fort holds four 280-millimetre Krupp guns with a range of 12 kilometres, and an observation post with a telescope and a pair of rangefinders that plotted approaching ships. Three arched tunnels underground, one of them 200 metres long, link the facilities and house ammunition depots and a generator room; most of the structure was designed to hide underground behind an «invisible curtain» of trees. It was decommissioned in 1972 and now sits in a 2.1-million-square-metre Atlantic Forest preserve. Tours began in 2016; they are free but must be booked in advance; check the days and times.
280 mm.
Underground.
Around the fort.
Morro do Monduba, Tombo, Guarujá, São Paulo state
Yes, tours are free but booked in advance by phone or email.