Chalkida ( Evia Greece ) is the capital of the island, connected to the mainland by a bridge and it is only about an hour away from Athens, so it's perfect for a day trip as well as holidays. There are many interesting sights in the town– a Castle of Karababa built on a hill above the city, the Red House and watching the tide phenomenon from the Negroponte Bridge. The Strait of Euripus is prone to extremely strong currents that reverse direction four times a day (roughly every six hours). The city has accommodation of all varieties, as well as shopping, cafes, bars, restaurants. There are several excellent nearby beaches – Agios Minas and Asteria are worth it for a dip!