DanubeThe Danube (ˈdæn.juːb ; ) is the second-longest river in Europe, after the Volga in Russia. It flows through much of Central and Southeastern Europe, from the Black Forest into the Black Sea. A large and historically important river, it was once a frontier of the Roman Empire and today connects ten European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , passing through or bordering Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova, and Ukraine.
Ancient Roman engineeringThe ancient Romans were famous for their advanced engineering accomplishments. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology inconceivable in Greece. The architecture used in Rome was strongly influenced by Greek and Etruscan sources. Roman roads Roads were common at that time, but the Romans improved their design and perfected the construction to the extent that many of their roads are still in use today.
Roman armyThe Roman army (Latin: exercitus Romanus) was the armed forces deployed by the Romans throughout the duration of Ancient Rome, from the Roman Kingdom (753 BC–509 BC) to the Roman Republic (509 BC–27 BC) and the Roman Empire (27 BC–476 AD), and its medieval continuation, the Eastern Roman Empire. It is thus a term that may span approximately 2,205 years (753 BC–1453 AD), during which the Roman armed forces underwent numerous permutations in size, composition, organisation, equipment and tactics, while conserving a core of lasting traditions.
Trajan's ColumnTrajan's Column (Colonna Traiana, Columna Traiani) is a Roman triumphal column in Rome, Italy, that commemorates Roman emperor Trajan's victory in the Dacian Wars. It was probably constructed under the supervision of the architect Apollodorus of Damascus at the order of the Roman Senate. It is located in Trajan's Forum, north of the Roman Forum. Completed in AD 113, the freestanding column is most famous for its spiral bas relief, which depicts the wars between the Romans and Dacians (101–102 and 105–106).
BridgeA bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations.