Dektenb was a continent on the planet Romulus.
It was noted as being an unstable region on the Romulan home world with tectonic plates that shifted against one another leading to the molten interior of the planet seeking the weak points in the crust. The flareups were frequent and immense with plumes of flame shooting miles into the sky and fires along with lava flows that glowed red as well as orange in serpentine patterns. This was a contributing factor to the wondrous Firefalls of Gal'Gathong.
As such, Dektenb was known as being unpredictable and volatile when compared to its neighboring continent of Masfarik. (TNG novelization: Unification)