The soil is mainly limestone-based, but in the valleys, there is a compact bank of volcanic tuff, the relic of an ancient volcano, located in Vigles, between the villages of Myrties and Kantouni.

The island is mainly barren, except for the two fertile valleys of Vathys and Pothia, where olives, oranges and vines are grown.

[4] Between Kalymnos and Kos lies the islet of Pserimos which is inhabited and, with an area of 11 square kilometres (4 sq mi), is one of the largest of the lesser islands of the Dodecanese.

According to the Ottoman General Census of 1881/82-1893, the kaza of Kalymnos had a total population of 9,716, consisting of 9,482 Greeks, 64 Muslims and 170 foreign citizens.

The local folk dance Mihanikos depicts the crippling effects of decompression sickness that is caused by sponge diving.

[11][12] The island has seen a boom in climbing related tourism since 1997, when the Italian Andrea di Bari started establishing the first routes.

Another industrial activity typical of Kalymnos was the production of painted head scarfs, which were the most original component of the female dress.

The cities of Darwin and Melbourne in Australia, and Tarpon Springs, Gary, IN, and Campbell, OH in the United States are home to large Greek communities of Kalymnian descent.

[citation needed] Kalymnian emigrants and their descendants also form a substantial portion of the bridge painting industry in the USA.

Some researchers link this to the sponge diving tradition and way of life as both trades involve dangerous work with long periods away from home.