Indicative rates, not an offer. Averaged from real buy and sell prices.
Greece uses the euro (EUR). US dollars, British pounds and Swiss francs are exchanged most often. Athens and Thessaloniki have the most offers, followed by Piraeus, Heraklion, Patras and the main island towns.
In summer, exchange offices open in resort areas, ports and on the islands, and airport rates are usually less favourable. In Greece, P2P offers let you swap USDT or USDC for euros or exchange US dollars directly with another person.
Below are exchange offices from open sources.