Greece
Athens in summer is reflective marble, treeless ruins, and a sun strong enough that locals avoid the streets between 1pm and 5pm entirely. The Acropolis enforces a knees-and-shoulders dress code at the gate, the marble surfaces of every ancient site are slippery enough that hiking sandals are recommended over flat-soled fashion sandals, and afternoon temperatures of 33-38°C / 91-100°F make linen non-negotiable. Athenians dress lighter and more uncovered than Romans — sleeveless dresses are common — but the religious sites (Acropolis, Plaka churches) shift the rule. The white-on-tan Mediterranean palette is the default.