Trölladyngja is a 275-meter-high volcanic mountain on the
Reykjanes Peninsula, located at the northern end of Núpshlíðarháls ridge.
Nearby stands Grænadyngja, which rises to 393 meters and closely resembles
Trölladyngja in shape. The two mountains are often referred to as twins
and are collectively known as Dyngjurnar.
Despite their names, Trölladyngja and Grænadyngja are not true shield
volcanoes and do not belong to that volcanic type. Nevertheless, they
are of great geological interest and illustrate the diverse volcanic
formations found on the Reykjanes Peninsula.
The southern slopes of the Dyngjurnar are particularly colorful and
host the high-temperature geothermal area known as Sogin, where geothermal
activity strongly shapes the landscape. The area is popular with hikers
and nature enthusiasts.
Both Trölladyngja and Grænadyngja are easy to climb, and their summits
offer excellent panoramic views across the Reykjanes Peninsula. The
upper part of Trölladyngja is somewhat rocky, adding character to the
ascent.
Several exploratory geothermal drill holes have been made in the
Trölladyngja area as part of past plans to harness geothermal energy.
These plans were eventually abandoned, as the drilling did not produce
sufficiently promising results.
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