Sillyon is one of the quieter ancient-city visits around Antalya, set on a steep hill above the Pamphylian plain. It lacks the manicured ease of Perge or Aspendos, but that roughness is part of the appeal: walls, gates, cisterns, and theatre remains scattered across a defensible height with long views toward the coast and mountains.
Come prepared for uneven ground and less interpretation than at the major ticketed sites. The reward is space and atmosphere. You can read the old city in fragments, moving from fortification lines to ruined public buildings while the modern agricultural plain stretches below. It is best for travellers who like archaeology with a bit of scrambling and silence.