Flights & getting there
Both Argos and Nafplio are hubs for the region and are well serviced by regional KTEL Argolis buses, including those from Isthmus (a transport hub to the Peloponnese).
There are bus services between Kranidi and Nafplio (€8.50, two hours, four weekdays, three on Saturday, one on Sunday), and local buses from Kranidi to Ermioni (€1.85, 10 minutes, several daily) and Porto Heli (€1.85, 10 minutes, several daily).
While you can reach major ancient sites by bus, your own wheels will give you far more flexibility.
Regular Hellenic Seaways high-speed passenger boats (three to four daily April to September, reduced service winter) depart from Porto Heli to Piraeus (€41.50, 3½ hours) via Spetses (€6.50, 10 minutes), Ermioni (also in the Peloponnese), Hydra (€17.50, 1¼ hours) and Poros (€22, two hours). Fares from Ermioni on this service are Hydra (€8.50, 25 minutes), Spetses (€8.50, 25 minutes), Poros (€17.50, 1¼ hours), Piraeus (€33.50, 2½ hours). Some faster services cut out intermediary stops.
The cheapest and most frequent boats to Hydra from Argolis are Hydra Lines from Metochi (€6.50, 15 minutes, hourly in summer, less frequently at other times); park for free by the waterfront or leave your car in a secure, shaded car park.
Caïques zip constantly between Galatas and Poros (€1, five minutes). Car ferries (passenger/car €1/6) also make this crossing.