Khalkís (Khalkída; pop: 37,000), chief town and port of the nomos of Euboea (which also includes the Petali Islands and Skyros), is attractively situated on a number of hills around the strait of Évripos, to the west of the ancient city. Its situation at the closest point to the mainland led to the development of a harbor at a very early stage,
and by 411 B.C. the town was also linked with the mainland by a timber bridge. At that time too the coastline was extended into the sea by the deposit of soil, thus further securing the vital connection with Boeotia against hostile attack. A rocky islet, on which is the Turkish fort of Karábaba, divides the strait into a western arm, now landlocked, and the broader eastern arm, spanned by a traversing bridge. A new bridge is under construction.
The Évripos is noted for its alternating currents, which change at least four times a day, and sometimes up to 20 times. The phenomenon, which was remarked on in ancient times, is thought to be due to interaction between the tides and areas of stagnant water.
The Latin alphabet is based on the script of ancient Chalkis.