Farum Brigantium

The Romans have been remembered through the ages as excellent engineers, and some of their constructions still stand (and are even in use) today. Examples include theaters and amphitheaters (like the one in Carthage that is still used for traditional performances), Roman bridges (like the longest-standing Roman bridge in Merida, Spain), and the lighthouse - the ancient Tower of Hercules in Spain.
The Tower of Hercules is one of only a very few Roman lighthouses still standing. Another Roman lighthouse can be seen at Dover Castle in England, where the old lighthouse was transformed into a church bell tower. The Lighthouse of Alexandria was an ancient Greek (or Ptolemy Egyptian) lighthouse and, like most lighthouses of ancient times, it has long since crumped (although people can see some ruins today).
The Tower of Hercules is the best-preserved Roman lighthouse by far. Not only that, it remains the only Roman lighthouse still in use, and it is thought to be the oldest extant lighthouse in the world.
Tower of Hercules: See The Oldest Standing Lighthouse In The World Built By The Romans