
Pula Arena
One of the world's best-preserved Roman amphitheatres.
Photo: Olgierd Rudak / CC BY-SA 4.0

Photo: Psittacuso / CC BY-SA 4.0
Descend into the tunnels Austro-Hungarian engineers carved under the hill to shelter the whole population from air raids. The passages stay refreshingly cool in summer and now host exhibitions and a planetarium. Follow them through the hill and emerge on the far side of the old town.
On a hot day, duck in to cool off: the WWI tunnels stay cellar-cold all summer.
A small next-step selection from the same city.

One of the world's best-preserved Roman amphitheatres.
Photo: Olgierd Rudak / CC BY-SA 4.0

Tito's island paradise of dinosaurs and safari.
Photo: Wikimedia Commons / CC BY-SA 4.0

Pula's oldest Roman monument, hiding in plain sight.
Photo: Berthold Werner / CC BY-SA 3.0
Use the free map from home, then verify the discovery when you reach the place.