Five minutes from downtown, the strategically located hilltop citadel is a good place to start your tour of Amman. The excellent views give perspective on the sprawling city—the sandstone buildings stretch to the horizon in every direction, but you'll have no trouble picking out the Roman theater. Not surprisingly, the citadel was an important fortress and archeological evidence shows that the area was occupied by human settlements as far back as the Paleolithic Age.
Impressive remains on the site include the Umayyad palace complex, dating from the 8th century, and the Roman Temple of Hercules. The Jordan Archaeology Museum here is worth a browse, though the collection is somewhat haphazardly organized.TIP: The ascent to the citadel is steep, 20-minute climb; you're best off taking a taxi up (about JD1 from downtown) and walking back downtown.