The Toledo Fortress (Alcazar) is a fortified square building with a tower at each corner. The Alcazar sits atop a promontory overlooking the city of Toledo, Spain, and the Tajo River valley. The building dates to the Roman era (3rd century AD) but was been restored many times in part because it has suffered damage from fires and bombardments. The building was extensively rebuilt between 1939 - 1957 due to damage inflicted during the siege of the Alcazar during the Spanish Civil War. Today the Alcazar houses an Army Museum.
You can see from the photo above how the Alcazar dominates the city and Tajo River valley.
Another important structure spanning the river is the Alcántara bridge (also known as Trajan's Bridge), which also dates back to Roman times (1st century AD). The bridge has also been extensively damaged in wars over the years, including with the Portuguese, French and Moors, and has required frequent extensive repairs, including the complete rebuilding of several arches.
The bridge is a multi-arch structure whose road is well above the water level.