Passages and hidden city
· Toompea
Ingrian Bastion
The Swedish-era Inger Bastion lies beneath Harjumägi, with a network of military passages inside its massive earthwork.
Inger Bastion was built in the 17th century, when artillery forced cities to supplement high walls with enormous earthworks. Thick soil absorbed the impact of shells, while internal passages allowed defenders to move under cover. Harjumägi now appears to be a peaceful park, but its shape remains military: the green slope covers a carefully engineered machine of defence.
Practical information
Address: Harjumägi
The outer form of the bastion can be viewed freely from Harjumägi. Underground sections are accessible only through an organised museum visit.